# Source code for tecplot.data.load

    from builtins import int, str

    import getpass
    import logging
    import os
    import platform
    import six
    import textwrap
    import warnings

    from ..tecutil import _tecutil, _tecutil_connector
    from ..constant import *
    from ..exception import *
    from .. import layout, macro, tecutil, version
    from ..tecutil import IndexSet, StringList, lock, sv

    log = logging.getLogger(__name__)

    @lock()
    def _tecplot_loader_load_data(arglist,
                                  frame,
                                  read_data_option=None,
                                  reset_style=None,
                                  initial_plot_first_zone_only=None,
                                  initial_plot_type=None,
                                  assign_strand_ids=None,
                                  add_zones_to_existing_strands=None):
        frame = frame or layout.active_frame()

        # If read_data_option is append and there is no data, we
        # need to silently change it to "Replace in Active Frame"
        if read_data_option == ReadDataOption.Append and (
                    not frame.has_dataset or frame.dataset.num_zones == 0):
            read_data_option = ReadDataOption.ReplaceInActiveFrame
        if read_data_option == ReadDataOption.ReplaceInActiveFrame:
            read_data_option = None  # Replace in active frame is the default

        with frame.activated():
            arglist.update(**{
                sv.READDATAOPTION: read_data_option,
                sv.RESETSTYLE: reset_style,
                sv.INITIALPLOTFIRSTZONEONLY: initial_plot_first_zone_only,
                sv.INITIALPLOTTYPE: initial_plot_type,
                sv.ASSIGNSTRANDIDS: assign_strand_ids,
                sv.ADDZONESTOEXISTINGSTRANDS: add_zones_to_existing_strands})

            if __debug__:
                msg = 'loading data:'
                for k, v in arglist.items():
                    if k == sv.FILENAMESORINSTRUCTIONS:
                        msg += '\n    {}:'.format(k)
                        for i in v:
                            msg += '\n        {}'.format(i)
                    else:
                        msg += '\n    {}: {}'.format(k, v)
                log.debug(msg)

            if not _tecutil.DataSetReadX(arglist):
                raise TecplotSystemError()

            return frame.dataset

    @lock()
    def load_converge_hdf5(filenames,
                           frame=None,
                           read_data_option=ReadDataOption.Append,
                           reset_style=None,
                           initial_plot_type=None):
        """Read CONVERGE HDF5 data files.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): CONVERGE HDF5 data
                files to be read. (See note below concerning absolute and relative
                paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type
                for the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic` (default), `Cartesian3D`, `Cartesian2D`,
                `XYLine`, `PlotType.Sketch`, `PolarLine`.

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        .. versionadded:: 2019.1
            Loading CONVERGE HDF5 data requires Tecplot 360 2019 R1 or later.

        .. versionadded:: 1.2
        """
        if isinstance(filenames, six.string_types):
            filenames = filenames.split(',')

        filenames = [tecutil.normalize_path(f) for f in filenames]

        if not _tecutil_connector.connected \
           or _tecutil_connector.client.host in ['localhost', '127.0.0.1']:
            for f in filenames:
                if not os.path.exists(f):
                    raise TecplotOSError('File not found: ' + f)

        with tecutil.StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'CONVERGE HDF5 File Loader'
                instr += ['FILELIST_DATAFILES', str(len(filenames))] + filenames
                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style,
                    initial_plot_type=initial_plot_type,
                    assign_strand_ids=True)

    @lock()
    def load_converge_output(filenames,
                             frame=None,

                             read_data_option=ReadDataOption.Append,
                             reset_style=None):
        """Read CONVERGE Output data files.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): CONVERGE Output data
                files to be read. (See note below concerning absolute and relative
                paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``
        """
        if isinstance(filenames, six.string_types):
            filenames = filenames.split(',')
        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'CONVERGE Output File Loader'
                instr += ['FILELIST', str(len(filenames))]
                instr += [tecutil.normalize_path(f) for f in filenames]
                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style)

    @lock()
    def load_fvcom(filenames,

                   frame=None,

                   read_data_option=ReadDataOption.Append,
                   reset_style=None,
                   initial_plot_type=None):
        """Read FVCOM netCDF data files.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): FVCOM data
                files to be read. (See note below concerning absolute and relative
                paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type
                for the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic` (default), `Cartesian3D`, `Cartesian2D`,
                `XYLine`, `PlotType.Sketch`, `PolarLine`.

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        .. versionadded:: 2018.2
            Loading FVCOM data requires Tecplot 360 2018 R2 or later.
        """
        if isinstance(filenames, six.string_types):
            filenames = filenames.split(',')
        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'FVCOM netCDF Loader'
                instr += ['FILELIST_DATAFILES', str(len(filenames))]
                instr += [tecutil.normalize_path(f) for f in filenames]
                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style,
                    initial_plot_type=initial_plot_type,
                    assign_strand_ids=True)

    @lock()
    def load_cgns(filenames,

                  frame=None,

                  read_data_option=ReadDataOption.Append,
                  reset_style=None,
                  initial_plot_first_zone_only=None,
                  initial_plot_type=None,

                  zones=None,
                  variables=None,

                  load_convergence_history=None,
                  combine_fe_sections=None,
                  average_to_nodes='Arithmetic',
                  uniform_grid=None,
                  assign_strand_ids=None,
                  add_zones_to_existing_strands=None,

                  include_boundary_conditions=True):
        """Read CGNS data files.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): CGNS data
                files to be read. (See note below concerning absolute and relative
                paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_first_zone_only (`bool`, optional): Informs
                the |Tecplot Engine| that after the data is loaded it only needs to
                activate the first enabled `Zone <data_access>` for the initial
                plot. This option is particularly useful if you have many `Zones
                <data_access>` and want to get the data into the |Tecplot Engine|
                and the first `Zone <data_access>` drawn as fast as possible. The
                inactive `Zones <data_access>` can always be activated when needed.
                (default: `False`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type
                for the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic` (default), `Cartesian3D`, `Cartesian2D`,
                `XYLine`, `PlotType.Sketch`, `PolarLine`.

            zones (`list` of `integers <int>`, optional): List of zone indexes to
                load starting from zero. `None` implies loading all zones.
                (default: `None`)
            variables (`list` of `integers <int>`, optional): List of variable
                indexes, beyond the first coordinate variables, to load starting
                from zero. `None` implies loading all variables. The grid will
                always be loaded and an index of zero indicates the first
                non-coordinate variable. (default: `None`)

            load_convergence_history (`bool`, optional): Load the
                global convergence history rather than any grid or solution data.
                (default: `False`)
            combine_fe_sections (`bool`, optional): Combine all
                finite-element sections with the zone cell-dimension into one
                zone. (default: `False`)
            average_to_nodes (`str`, optional): Average
                cell-centered data to grid nodes using the specified method.
                (Options: `None`, "Arithmetic", "Laplacian", default: "Arithmetic")
            uniform_grid (`bool`, optional): Indicates the grid
                structure is the same for all time steps. (default: `True`)
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `False`)

            include_boundary_conditions (`bool`, optional): Load the
                boundary conditions along with the data. Upon loading, the
                associated fieldmaps will remain inactive. For unstructured data,
                boundary conditions are always loaded and this option is ignored.
                (default: `True`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        Raises:
            `TecplotSystemError`: Internal error when loading data.
            `TecplotTypeError`: Invalid input.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``
        """
        if __debug__:
            avg_to_nodes_opts = [None, 'Arithmetic', 'Laplacian']
            if average_to_nodes not in avg_to_nodes_opts:
                msg = 'average_to_nodes must be one of: '
                msg += ', '.join(str(x) for x in avg_to_nodes_opts)
                raise TecplotTypeError(msg)

        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'CGNS LOADER'
                instr += ['LoaderVersion', 'V3']

                # We need to add the cgns library version to the arglist,
                # although this setting is not exposed in the API.
                instr += ['CgnsLibraryVersion', '3.1.4']

                if isinstance(filenames, six.string_types):
                    filenames = filenames.split(',')
                instr += ['FILELIST_CGNSFILES', str(len(filenames))]
                instr += [tecutil.normalize_path(f) for f in filenames]

                if zones is not None:
                    indexes = [str(int(z)) for z in zones]
                    instr += ['ZoneList', ','.join(indexes)]
                if variables is not None:
                    indexes = [str(int(v)) for v in variables]
                    instr += ['VarList', ','.join(indexes)]

                if average_to_nodes is None:
                    instr += ['AverageToNodes', 'No']
                elif average_to_nodes != 'Arithmetic':
                    # Default for 'AverageToNoes' is 'Yes'
                    # Default for AveragingMethods is 'Arithmetic'
                    instr += ['AveragingMethod', average_to_nodes]

                if uniform_grid is not None:
                    instr += ['UniformGridStructure',
                              'Yes' if uniform_grid else 'No']

                if combine_fe_sections is not None:
                    instr += [
                        'SectionLoad', 'SeparateZones'
                        if combine_fe_sections else 'Combine']
                if include_boundary_conditions is not None:
                    instr += ['LoadBCs',
                              'Yes' if include_boundary_conditions else 'No']
                if load_convergence_history is not None:
                    instr += ['LoadConvergenceHistory',
                              'Yes' if load_convergence_history else 'No']
                if assign_strand_ids is not None:
                    instr += ['AssignStrandIDs',
                              'Yes' if assign_strand_ids else 'No']

                arglist[sv.FILENAMESORINSTRUCTIONS] = instr

                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style,
                    initial_plot_first_zone_only=initial_plot_first_zone_only,
                    initial_plot_type=initial_plot_type,
                    assign_strand_ids=assign_strand_ids,
                    add_zones_to_existing_strands=add_zones_to_existing_strands)

    @lock()
    def load_fluent(case_filenames=None,
                    data_filenames=None,

                    frame=None,

                    append=True,
                    zones=None,
                    variables=None,

                    all_poly_zones=None,
                    average_to_nodes='Arithmetic',
                    time_interval=None,
                    assign_strand_ids=True,
                    add_zones_to_existing_strands=None,

                    include_particle_data=None,
                    include_additional_quantities=True,
                    save_uncompressed_files=None):
        """Read Fluent data files.

        Parameters:
            case_filenames (`str` or `list` of `strings <str>`, optional):
                Case (*.cas*, *.cas.gz*) files to be read. Compressed files with
                extension *.gz* are supported. (See note below concerning absolute
                and relative paths.)
            data_filenames (`str` or `list` of `strings <str>`, optional):
                Data (*.dat*, *.xml*, *.dat.gz*, *.fdat*, *.fdat.gz*, etc.) files
                to be read. Compressed files with extension *.gz* are supported.
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            append (`bool`, optional): Append the data to the existing
                `Dataset`. If `False`, the existing data attached to the `Frame` is
                deleted and replaced. (default: `True`)

            zones (`str` or `list` of `integers <int>`, optional): List of
                zone indexes (zero-based) to load or string specifying the type of
                zones to load. Possible values are: "CellsAndBoundaries",
                "CellsOnly" and "BoundariesOnly". Specifying one of these options
                is mutually exclusive with the ``variables`` option. (default:
                "CellsAndBoundaries")
            variables (`list` of `strings <str>`, optional): List of variable
                names to load. `None` implies loading all variables. (default:
                `None`)

            all_poly_zones (`bool`, optional): Converts all zones to
                Tecplot polytope (polyhedral or polygonal) zones. (default:
                `False`)
            average_to_nodes (`str`, optional): Average
                cell-centered data to grid nodes using the specified method.
                (Options: `None`, "Arithmetic", "Laplacian", default: "Arithmetic")
            time_interval (`float`, optional): Use a constant time interval between
                each data (*.dat*) file. If `None`, the flow-data parameter of each
                solution data (*.dat*) file is used. (default: `None`)
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)

                .. note::
                    assign_strand_ids only applies if you have also provided a
                    time_interval, otherwise it will be ignored.
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `False`)

            include_particle_data (`bool`, optional): Load particle
                data from the data (*.dat*) files. If loading particle data from an XML
                file, the XML file should be included in the ``data_filenames``
                list. (default: `False`)
            include_additional_quantities (`bool`, optional): Load
                quantities that were derived from the FLUENT's standard quantities.
                (default: `True`) *New in Tecplot 360 2017 R2*.
            save_uncompressed_files (`bool`, optional): Save the
                uncompressed files to the compressed files' location.

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        Raises:
            `TecplotSystemError`: Internal error when loading data.
            `TecplotTypeError`: In-valid input.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        Notes:
            The ``zones`` option takes either a `list` of zone indexes to be
            imported or one of "CellsAndBoundaries", "CellsOnly" or
            "BoundariesOnly" to indicate the type of zones the user wants to load,
            however these options are mutually exclusive with the ``variables``
            option::

                >>> dataset = tecplot.data.load_fluent(['one.cas', 'two.cas'],
                ...     data_filenames=['one.dat', 'two.dat'],
                ...     variables = ['Pressure','Velocity'],
                ...     zones = [0,1,3])
        """
        if isinstance(case_filenames, six.string_types):
            case_filenames = [case_filenames]
        if isinstance(data_filenames, six.string_types):
            data_filenames = [data_filenames]

        if __debug__:
            zone_types_opts = ['CellsAndBoundaries', 'CellsOnly', 'BoundariesOnly']
            avg_to_nodes_opts = [None, 'Arithmetic', 'Laplacian']
            if isinstance(zones, six.string_types):
                if zones not in zone_types_opts:
                    msg = 'Zones must be list of indexes or one of: '
                    msg += ', '.join(zone_types_opts)
                    raise TecplotTypeError(msg)
                if variables is not None:
                    msg = 'Loading a subset of variables is allowed only if'
                    msg += ' zones is None or a list of zones.'
                    raise TecplotTypeError(msg)
            if (case_filenames or data_filenames) is None:
                raise TecplotTypeError('You must specify a case or data file.')
            if (case_filenames is None) and (len(data_filenames) != 1):
                msg = 'Case file is required when loading multiple data files'
                raise TecplotTypeError(msg)
            if average_to_nodes not in avg_to_nodes_opts:
                msg = 'average_to_nodes must be one of: '
                msg += ', '.join(str(x) for x in avg_to_nodes_opts)
                raise TecplotTypeError(msg)

            if include_additional_quantities:
                sdk_required = (2017, 2)
                if version.sdk_version_info < sdk_required:
                    def format_msg(msg):
                        """reflow message, adjusting spaces"""
                        msg = textwrap.dedent(' '.join(msg.split()))
                        return textwrap.fill(msg, width=60)
                    msg = 'Out-of-date Tecplot 360.\n'
                    msg += format_msg('''\
                        Loading of FLUENT's additional quantities requires Tecplot
                        360 version {} R{} or later. Data will be loaded without
                        these additional quantities.'''.format(*sdk_required))
                    warnings.warn(msg)

        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'Fluent Data Loader'

                if append:
                    instr += ['Append', 'Yes']

                if case_filenames is not None:
                    if data_filenames is not None:
                        nfiles = len(case_filenames) + len(data_filenames)
                        instr += ['LoadOption', 'MultipleCaseAndData',
                                  'FILELIST_Files', str(nfiles)]
                        instr += [tecutil.normalize_path(f)
                                  for f in list(case_filenames) +
                                  list(data_filenames)]
                    else:
                        instr += ['LoadOption', 'MultipleCaseAndData',
                                  'FILELIST_Files', str(len(case_filenames))]
                        instr += [tecutil.normalize_path(f)
                                  for f in list(case_filenames)]
                else:
                    instr += ['LoadOption', 'ResidualsOnly',
                              'FILENAME_DataFile',
                              tecutil.normalize_path(data_filenames[0])]

                if time_interval is not None:
                    instr += ["UnsteadyOption", 'ApplyConstantTimeInterval']
                    instr += ['TimeInterval', str(float(time_interval))]

                if isinstance(zones, six.string_types):
                    instr += ['GridZones', zones]
                elif (zones or variables) is not None:
                    instr += ["GridZones", 'SelectedZones']
                    if zones is not None:
                        zone_indexes = ','.join(str(int(z) + 1) for z in zones)
                        instr += ['ZoneList', zone_indexes]
                    if variables is not None:
                        var_names = '\n'.join(variables)
                        instr += ['VarNameList', var_names]

                if include_particle_data:  # "No" is the default
                    instr += ['IncludeParticleData',
                              'Yes']
                if all_poly_zones:  # "No" is the default
                    instr += ['AllPolyZones',
                              'Yes']
                if average_to_nodes is None:
                    instr += ['AverageToNodes', 'No']
                elif average_to_nodes != 'Arithmetic':
                    # Default for 'AverageToNoes' is 'Yes'
                    # Default for AveragingMethods is 'Arithmetic'
                    instr += ['AveragingMethod', average_to_nodes]

                if assign_strand_ids is not None:
                    instr += ['AssignStrandIDs',
                              'Yes' if assign_strand_ids else 'No']
                if add_zones_to_existing_strands is not None:
                    instr += ['AddZonesToExistingStrands',
                              'Yes' if add_zones_to_existing_strands else 'No']

                # Always explicitly provide SaveUncompressedFiles
                instr += ['SaveUncompressedFiles',
                          'Yes' if save_uncompressed_files else 'No']

                if version.sdk_version_info >= (2017, 2):
                    instr += ['LoadAdditionalQuantities',
                              'Yes' if include_additional_quantities else 'No']

                arglist[sv.FILENAMESORINSTRUCTIONS] = instr

                return _tecplot_loader_load_data(arglist, frame=frame)

    @lock()
    def load_fluent_cff(filenames,
                        frame=None,
                        read_data_option=ReadDataOption.Append,
                        reset_style=None,
                        initial_plot_type=None,
                        solution_time_source=None,
                        include_interior_face_zones=None,
                        include_particle_zones=None):
        """Read Fluent Common Fluids Format files.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): One or more Fluent CFF
                case (*.cas.h5*) files followed by zero or more Fluent CFF data
                (*.dat.h5*) files (See note below concerning absolute and relative
                paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type for
                the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic`, `Cartesian3D`, `Cartesian2D`, `XYLine`,
                `PlotType.Sketch`, `PolarLine`. (default: `PlotType.Automatic`)
            solution_time_source (`FluentCFFLoader.SolutionTimeSource`, optional):
                Assign the solution times of the zones based on the specified
                criteria. (default: `FluentCFFLoader.SolutionTimeSource.Auto`)

                Possible values are:
                    * `FluentCFFLoader.SolutionTimeSource.Auto`
                        First looks for and uses solution time specified in the
                        simulation settings of the Fluent CFF data files. If that
                        information isn't present in all supplied files, next looks
                        for solution time embedded in ``filenames``. If solution
                        time cannot be determined, the loader assigns a constant
                        time interval, starting at zero and incrementing by one, if
                        there is a single file, or if there are case and data file
                        combinations, otherwise assigns static solution times of
                        zero.
                    * `FluentCFFLoader.SolutionTimeSource.SteadyState`
                        Assigns a static solution time of zero to all zones.
                    * `FluentCFFLoader.SolutionTimeSource.ConstantTimeInterval`
                        Assigns a constant time interval, starting at zero and
                        incrementing by one
            include_interior_face_zones (`bool`, optional): Interior face zones,
                which are used to build cell zones, are loaded as independent
                face zones. (default: `False`)
            include_particle_zones (`bool`, optional): Loads particle data as
                I-ordered zones and nodal variables if it exists in the data
                (*dat.h5*) file(s). (default: `True`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        .. note::
            The Fluent CFF loader is not available on macOS.

        The Fluent CFF loader takes one or more case files, followed by zero or
        more data files in a single list::

            >>> dataset = tecplot.data.load_fluent_cff(
            ...     ['one.cas.h5', 'one.dat.h5', 'two.dat.h5', 'three.cas.h5'],
            ...     read_data_option = ReadDataOption.Replace,
            ...     include_interior_face_zones = True)

        .. versionadded:: 2021.1
            Loading Fluent CFF files requires Tecplot 360 2021 R1 or later.

        .. versionadded:: 1.4
        """
        if isinstance(filenames, six.string_types):
            filenames = filenames.split(',')

        filenames = [tecutil.normalize_path(f) for f in filenames]

        TimeSource = FluentCFFLoader.SolutionTimeSource
        with tecutil.StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'Fluent Common Fluid Files Loader'
                instr += ['FILELIST_DATAFILES', str(len(filenames))] + filenames
                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                if solution_time_source is not None:
                    instr += ['SolutionTimeSource',
                              TimeSource(solution_time_source).value]
                if include_interior_face_zones: # 'No' is the default
                    instr += ['IncludeInteriorFaceZones', 'Yes']
                if include_particle_zones is False:
                    instr += ['IncludeParticleZones', 'No']
                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style,
                    initial_plot_type=initial_plot_type,
                    assign_strand_ids=True)

    @lock()
    def load_telemac(filenames=None,
                     boundary_filename=None,
                     frame=None,
                     read_data_option=ReadDataOption.Append,
                     reset_style=None,
                     initial_plot_type=None):
        """Read Telemac data files and/or boundary file.

        Parameters:
            filenames (`str` or `list` of `strings <str>`, optional): Telemac data
                file(s) to be read. (See note below concerning absolute and
                relative paths.) Not required if a boundary file is being appended
                to an existing data set.
            boundary_filename (`str`, optional): Boundary file. If loaded with
                multiple Telemac files, will be applied to the first Telemac file.
                If loaded with no Telemac files, must be appended to an existing
                data set (read_data_option must be `ReadDataOption.Append`, the
                default).
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type for
                the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic`, `Cartesian3D`, `Cartesian2D`, `XYLine`,
                `PlotType.Sketch`, `PolarLine`. (default: `PlotType.Automatic`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        .. versionadded:: 2019.1
            Loading Telemac data requires Tecplot 360 2019 R1 or later.
        """
        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'Telemac Data Loader'

                if filenames is not None:
                    if isinstance(filenames, six.string_types):
                        filenames = filenames.split(',')
                    instr += ['FILELIST_TELEMAC', str(len(filenames))]
                    instr += [tecutil.normalize_path(f) for f in filenames]

                if boundary_filename is not None:
                    instr += ['FILENAME_BOUNDARY',
                              tecutil.normalize_path(boundary_filename)]

                arglist[sv.FILENAMESORINSTRUCTIONS] = instr

                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style,
                    initial_plot_type=initial_plot_type,
                    assign_strand_ids=True)

    @lock()
    def load_plot3d(grid_filenames=None,
                    solution_filenames=None,
                    function_filenames=None,
                    name_filename=None,

                    frame=None,

                    append=True,
                    # setting any of these three implies auto_detect=False
                    data_structure=None,  # (1D|2D|3DP|3DW|UNSTRUCTURED)
                    is_multi_grid=None,  # (True|False)
                    style=None,  # (PLOT2DCLASSIC|PLOT3DFUNCTION|OVERFLOW)

                    ascii_is_double=None,  # (True|False)
                    ascii_has_blanking=None,  # (True|False)
                    uniform_grid=None,  # (True|False)

                    assign_strand_ids=True,
                    add_zones_to_existing_strands=True,
                    append_function_variables=None,  # (True|False)
                    include_boundaries=True):
        """Read Plot3D data files.

        Parameters:
            grid_filenames (`list` of `strings <str>`, optional): One or more grid
                file names to be read. (See note below concerning absolute and
                relative paths.)
            solution_filenames (`list` of `strings <str>`, optional): One or more
                solution data file names to be read.
            function_filenames (`list` of `strings <str>`, optional): One or more
                function file names.
            name_filename (`str`, optional): Path to the name file.
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            append (`bool`, optional): Append the data to the existing
                `Dataset`. If `False`, the existing data attached to the `Frame` is
                deleted and replaced. (default: `True`)
            data_structure (`str`, optional): Specifies the data
                structure and overrides the automatic detection. Options are:
                ``1D``, ``2D``, ``3DP``, ``3DW``, ``UNSTRUCTURED``. Setting this
                requires ``is_multi_grid`` and ``style`` to be set as well.
            is_multi_grid (`bool`, optional): Sets data as multi-grid
                and overrides the automatic data structure detection. Setting
                this requires ``data_structure`` and ``style`` to be set as well.
            style (`bool`, optional): Specifies the data style and
                overrides the automatic data structure detection. Options are:
                ``PLOT3DCLASSIC``, ``PLOT3DFUNCTION``, ``OVERFLOW``. Setting this
                requires ``data_structure`` and ``is_multi_grid`` to be set as
                well.

            ascii_is_double (`bool`, optional): Indicates that
                floating-point numbers found in the text data files should be
                store with 64-bit precision. (default: `False`)
            ascii_has_blanking (`bool`, optional): Indicates that the
                text data files contain blanking. (default: `False`)
            uniform_grid (`bool`, optional): Indicates the grid
                structure is the same for all time steps. (default: `True`)

            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `True`)
            append_function_variables (`bool`, optional): Append
                variables in function files to those found in solution files.
                (default: `False`)
            include_boundaries (`bool`, optional): Loads boundary zones
                found in the ".g.fvbnd" file located in the same directory as the
                grid file, if available. (default: `True`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        Raises:
            `TecplotSystemError`: Internal error when loading data.
            `TecplotValueError`: In-valid input.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        .. note:: Data structure is automatically detected by default.

            The options ``data_structure``, ``is_multi_grid`` and ``style``
            must be supplied together or not at all. When all of these are
            `None`, the data structure is automatically detected.

        The variables from the function files can be appended to the dataset
        upon loading::

            >>> dataset = tecplot.data.load_plot3d(
            ...     grid_filenames = 'data.g',
            ...     solution_filenames = ['t0.q', 't1.q'],
            ...     function_filenames = ['t0.f', 't1.f'],
            ...     append_function_variables = True)
        """
        if isinstance(grid_filenames, six.string_types):
            grid_filenames = [grid_filenames]
        if isinstance(solution_filenames, six.string_types):
            solution_filenames = [solution_filenames]
        if isinstance(function_filenames, six.string_types):
            function_filenames = [function_filenames]

        if __debug__:
            data_structure_opts = [None, '1D', '2D', '3DP', '3DW', 'UNSTRUCTURED']
            style_opts = [None, 'PLOT3DCLASSIC', 'PLOT3DFUNCTION', 'OVERFLOW']
            if data_structure not in data_structure_opts:
                msg = 'data_structure must be one of: '
                msg += ', '.join(str(x) for x in data_structure_opts)
                raise TecplotValueError(msg)
            if style not in style_opts:
                msg = 'style must be one of: '
                msg += ', '.join(str(x) for x in style_opts)
                raise TecplotValueError(msg)
            if grid_filenames and solution_filenames:
                if len(grid_filenames) != 1 and \
                   len(grid_filenames) != len(solution_filenames):
                    raise TecplotValueError(textwrap.dedent('''\
                        You must specify a single grid file or
                        the same number of grid and solution files.'''))
            autodetect_opts = [data_structure, is_multi_grid, style]
            if sum([x is None for x in autodetect_opts]) not in [0, 3]:
                raise TecplotValueError(textwrap.dedent('''\
                    The options: data_structure, is_multi_grid and style
                    must be supplied all together or not at all.'''))

        frame = frame or layout.active_frame()

        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'PLOT3D Loader'

                preexisting_dataset = frame.has_dataset and frame.dataset.num_zones
                if append is not None:
                    if append:
                        if preexisting_dataset:
                            instr += ['Append', 'Yes']
                    else:
                        instr += ['Append', 'No']

                if grid_filenames is not None:
                    instr += ['FILELIST_GRIDFILES', str(len(grid_filenames))]
                    instr += [tecutil.normalize_path(f) for f in grid_filenames]
                if solution_filenames is not None:
                    instr += ['FILELIST_SOLUTIONFILES',
                              str(len(solution_filenames))]
                    instr += [tecutil.normalize_path(f) for f in solution_filenames]
                if function_filenames is not None:
                    instr += ['FILELIST_FUNCTIONFILES',
                              str(len(function_filenames))]
                    instr += [tecutil.normalize_path(f) for f in function_filenames]
                if name_filename is not None:
                    instr += ['FILENAME_NAMEFILE',
                              tecutil.normalize_path(name_filename)]

                if (data_structure or is_multi_grid or style) is None:
                    instr += ['AUTODETECT', 'Yes']
                else:
                    instr += ['AUTODETECT', 'No']
                    instr += ['DATASTRUCTURE', data_structure]
                    instr += ['ISMULTIGRID', 'Yes' if is_multi_grid else 'No']
                    instr += ['STYLE', style]

                if ascii_is_double is not None:
                    instr += ['ASCIIISDOUBLE', 'Yes' if ascii_is_double else 'No']
                if ascii_has_blanking is not None:
                    instr += ['ASCIIHASBLANK',
                              'Yes' if ascii_has_blanking else 'No']

                if uniform_grid is not None:
                    instr += ['UNIFORMGRIDSTRUCTURE',
                              'Yes' if uniform_grid else 'No']
                if assign_strand_ids is not None:
                    instr += ['ASSIGNSTRANDIDS',
                              'Yes' if assign_strand_ids else 'No']
                if add_zones_to_existing_strands is not None:
                    if preexisting_dataset:
                        instr += ['ADDTOEXISTINGSTRANDS',
                                  'Yes' if add_zones_to_existing_strands else 'No']

                if append_function_variables is not None:
                    if solution_filenames or preexisting_dataset:
                        instr += ['APPENDFUNCTIONVARIABLES',
                                  'Yes' if append_function_variables else 'No']
                if include_boundaries is not None:
                    instr += ['LOADBOUNDARY', 'Yes' if include_boundaries else 'No']

                arglist[sv.FILENAMESORINSTRUCTIONS] = instr

                try:
                    return _tecplot_loader_load_data(arglist, frame=frame)
                except TecplotLogicError as e:
                    if str(e).startswith('The boundary file does not'):
                        log.warning(e)
                        return layout.active_frame().dataset
                    raise

    @lock()
    def load_cfx(filename,
                 frame=None,
                 append=True,
                 assign_strand_ids=True,
                 add_zones_to_existing_strands=True,
                 initial_plot_type=PlotType.Automatic):
        """Read an ANSYS CFX data file.

        Parameters:
            filename (`str`): The data file to be read. (See note below concerning
                absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            append (`bool`, optional): Append the data to the existing
                `Dataset`. If `False`, the existing data attached to the `Frame` is
                deleted and replaced. (default: `True`)
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `True`)
            initial_plot_type (`PlotType`, optional): Set the initial plot type
                upon loading of the data. Must be one of `PlotType.Automatic`
                (default), `PlotType.Cartesian3D` or `PlotType.Cartesian2D`.

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        .. note::
            The CFX loader is not available on macOS.
        """
        if platform.system() == 'Darwin':
            msg = 'CFX data loader is not available on macOS'
            raise TecplotNotImplementedError(msg)
        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'ANSYS CFX (FEA)'
                instr += ['FEALoaderVersion', FEALoader.Version.Current.value]
                instr += ['FILENAME_File', tecutil.normalize_path(filename)]

                frame = frame or layout.active_frame()
                preexisting_dataset = frame.has_dataset and frame.dataset.num_zones
                if preexisting_dataset:
                    instr += ['Append', 'Yes' if append else 'No']
                    instr += ['AddToExistingStrands',
                              'Yes' if add_zones_to_existing_strands else 'No']

                instr += ['AutoAssignStrandIDs',
                          'Yes' if assign_strand_ids else 'No']
                initplottype = PlotType(initial_plot_type)
                if initplottype != PlotType.Automatic:
                    instr += ['InitialPlotType', initplottype.name]

                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(arglist, frame=frame)

    @lock()
    def load_ensight(filename,
                     frame=None,
                     read_data_option=ReadDataOption.Append,
                     reset_style=None,
                     initial_plot_first_zone_only=None,
                     initial_plot_type=None,
                     assign_strand_ids=True,
                     add_zones_to_existing_strands=None):
        """Read Ensight data files and/or boundary file.

        Parameters:
            filename (`str`): The case file to be read. (See note below concerning
                absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type for
                the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic`, `Cartesian3D`, `Cartesian2D`, `XYLine`,
                `PlotType.Sketch`, `PolarLine`. (default: `PlotType.Automatic`)
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `True`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``
        """
        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'EnSight Loader'
                instr += ['FILENAME_CASEFILE', tecutil.normalize_path(filename)]
                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style,
                    initial_plot_first_zone_only=initial_plot_first_zone_only,
                    initial_plot_type=initial_plot_type,
                    assign_strand_ids=assign_strand_ids,
                    add_zones_to_existing_strands=add_zones_to_existing_strands)

    '''
    @lock()
    def load_kiva(filenames,
                  frame=None,
                  is_double=True,
                  load_particle_data=True,
                  velocity_vector='u_vel',
                  dataset_title=None):
        """Read Kiva/GMV data files.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): The data file(s) to be
                read. (See note below concerning absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            is_double (`bool`, optional): Allows greater precision for your data
                values. (default: `True`)
            load_particle_data (`bool`, optional): Adds a zone for any files
                containing particle data. (default: `True`)
            velocity_vector (`str`, optional): Identify the naming convention for
                your velocity vectors. This is the name of the first component (u)
                and is typically one of: "u_vel" (default), "u-vel" or "u".
            dataset_title (`str`, optional): The name of the resulting `Dataset` in
                Tecplot. (default: `None`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``
        """
        if isinstance(filenames, six.string_types):
            filenames = [filenames]
        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'Kiva Loader'
                instr += ['FILELIST_DataFiles', str(len(filenames))]
                instr += [tecutil.normalize_path(f) for f in filenames]
                instr += ['ISDOUBLE', 'YES' if is_double else 'No']
                instr += ['LOADPARTICLEDATA', 'YES' if load_particle_data else 'No']
                instr += ['VELVECTOR', str(velocity_vector)]
                if dataset_title:
                    instr += ['DATASETTITLE', str(dataset_title)]
                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(arglist, frame)
    '''

    @lock()
    def load_openfoam(
        filename,
        frame=None,
        append=True,
        boundary_zone_construction=None,
        assign_strand_ids=True,
        add_zones_to_existing_strands=True,
        initial_plot_type=PlotType.Automatic,
        initial_plot_first_zone_only=False
    ):
        """Read an OpenFOAM data file.

        Parameters:
            filename (`str`): The data file to be read. (See note below concerning
                absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            append (`bool`, optional): Append the data to the existing
                `Dataset`. If `False`, the existing data attached to the `Frame` is
                deleted and replaced. (default: `True`)
            boundary_zone_construction (`OpenFOAMLoader.BoundaryZoneConstruction`, optional):
                Set how the boundary zones are constructed. This may be either
                `OpenFOAMLoader.BoundaryZoneConstruction.Reconstructed` (default)
                or `OpenFOAMLoader.BoundaryZoneConstruction.Decomposed`. This
                option requires Tecplot 360 2019 R1 or later.
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `True`)
            initial_plot_type (`PlotType`, optional): Set the initial plot type
                upon loading of the data. Must be one of `PlotType.Automatic`
                (default), `PlotType.Cartesian3D` or `PlotType.Cartesian2D`.
            initial_plot_first_zone_only (`bool`, optional): Informs
                the |Tecplot Engine| that after the data is loaded it only needs to
                activate the first enabled `Zone <data_access>` for the initial
                plot. This option is particularly useful if you have many `Zones
                <data_access>` and want to get the data into the |Tecplot Engine|
                and the first `Zone <data_access>` drawn as fast as possible. The
                inactive `Zones <data_access>` can always be activated when needed.
                (default: `False`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        .. warning:: **Zone and variable ordering may change between releases**

            Due to possible changes in data loaders or data formats over time, the
            ordering of zones and variables may be different between versions of
            Tecplot 360. Therefore it is recommended to always reference zones and
            variables **by name** instead of by index.
        """
        if __debug__:
            if (
                boundary_zone_construction is not None and
                version.sdk_version_info < (2018, 3)
            ):
                msg = 'boundary_zone_construction' + \
                      ' requires Tecplot 360 2019 R1 or later'
                raise TecplotOutOfDateEngineError((2019, 1), msg)

        if isinstance(boundary_zone_construction, BoundaryZoneConstruction):
            enum_value = boundary_zone_construction.value
            boundary_zone_construction = \
                OpenFOAMLoader.BoundaryZoneConstruction(enum_value)
            if __debug__:
                tecutil.api_moved('BoundaryZoneConstruction',
                                  'OpenFOAMLoader.BoundaryZoneConstruction',
                                  '1.4', '2021 R1', warning=True)

        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'OpenFOAM (FEA)'

                instr += ['FEALoaderVersion', FEALoader.Version.Current.value]
                instr += ['FILENAME_File', tecutil.normalize_path(filename)]

                frame = frame or layout.active_frame()
                preexisting_dataset = frame.has_dataset and frame.dataset.num_zones
                if preexisting_dataset:
                    instr += ['Append', 'Yes' if append else 'No']
                    instr += ['AddToExistingStrands',
                              'Yes' if add_zones_to_existing_strands else 'No']

                instr += ['AutoAssignStrandIDs',
                          'Yes' if assign_strand_ids else 'No']
                initplottype = PlotType(initial_plot_type)
                if initplottype != PlotType.Automatic:
                    instr += ['InitialPlotType', initplottype.name]
                instr += ['ShowFirstZoneOnly',
                          'Yes' if initial_plot_first_zone_only else 'No']

                if version.sdk_version_info >= (2018, 3):
                    BZCon = OpenFOAMLoader.BoundaryZoneConstruction
                    if boundary_zone_construction is None:
                        bzcon = BZCon.Reconstructed
                    else:
                        bzcon = BZCon(boundary_zone_construction)
                    instr += ['BoundaryZoneConstruction', bzcon.value]

                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(arglist, frame=frame)

    @lock()
    def load_stl(filename,
                 frame=None,
                 append=True,
                 subdivide_zones=STLLoader.SubdivideZones.DoNotSubdivide,
                 assign_strand_ids=True,
                 add_zones_to_existing_strands=True,
                 initial_plot_type=PlotType.Automatic,
                 initial_plot_first_zone_only=False):
        """Read a 3D Systems STL data file.

        Parameters:
            filename (`str`): The data file to be read. (See note below concerning
                absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            append (`bool`, optional): Append the data to the existing
                `Dataset`. If `False`, the existing data attached to the `Frame` is
                deleted and replaced. (default: `True`)
            subdivide_zones (`STLLoader.SubdivideZones`, optional): Specify method
                of zone division. Possible values are:
                `STLLoader.SubdivideZones.DoNotSubdivide` (default),
                `STLLoader.SubdivideZones.ByComponent` and
                `STLLoader.SubdivideZones.ByElementType`.
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `True`)
            initial_plot_type (`PlotType`, optional): Set the initial plot type
                upon loading of the data. Must be one of `PlotType.Automatic`
                (default), `PlotType.Cartesian3D` or `PlotType.Cartesian2D`.
            initial_plot_first_zone_only (`bool`, optional): Informs
                the |Tecplot Engine| that after the data is loaded it only needs to
                activate the first enabled `Zone <data_access>` for the initial
                plot. This option is particularly useful if you have many `Zones
                <data_access>` and want to get the data into the |Tecplot Engine|
                and the first `Zone <data_access>` drawn as fast as possible. The
                inactive `Zones <data_access>` can always be activated when needed.
                (default: `False`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``
        """
        if isinstance(subdivide_zones, SubdivideZones):
            subdivide_zones = STLLoader.SubdivideZones(subdivide_zones.value)
            if __debug__:
                tecutil.api_moved('SubdivideZones', 'STLLoader.SubdivideZones',
                                  '1.4', '2021 R1', warning=True)

        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = '3D Systems STL (FEA)'
                instr += ['FEALoaderVersion', FEALoader.Version.Current.value]
                instr += ['FILENAME_File', tecutil.normalize_path(filename)]

                frame = frame or layout.active_frame()
                preexisting_dataset = frame.has_dataset and frame.dataset.num_zones
                if preexisting_dataset:
                    instr += ['Append', 'Yes' if append else 'No']
                    instr += ['AddToExistingStrands',
                              'Yes' if add_zones_to_existing_strands else 'No']

                subdiv = STLLoader.SubdivideZones(subdivide_zones)
                if subdiv != STLLoader.SubdivideZones.DoNotSubdivide:
                    instr += ['SubdivideZonesBy', subdiv.value]
                instr += ['AutoAssignStrandIDs',
                          'Yes' if assign_strand_ids else 'No']
                initplottype = PlotType(initial_plot_type)
                if initplottype != PlotType.Automatic:
                    instr += ['InitialPlotType', initplottype.name]
                instr += ['ShowFirstZoneOnly',
                          'Yes' if initial_plot_first_zone_only else 'No']

                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(arglist, frame=frame)

    @lock()
    def load_vtk(filenames,
                 frame=None,
                 read_data_option=ReadDataOption.Append,
                 reset_style=True,
                 initial_plot_type=PlotType.Automatic,
                 assign_strand_ids=True,
                 add_zones_to_existing_strands=False,
                 solution_time_source=VTKLoader.SolutionTimeSource.Auto):
        """Read VTK data files.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): The data file(s) to be
                read. (See note below concerning absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        The `DataSet` in the active frame is replaced by the new
                        `DataSet`. If other frames were using the same `DataSet`
                        originally in the active frame, they will continue to use
                        it.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame, and to
                        all other frames that use the same `DataSet`.

                    Default: `ReadDataOption.Append`
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type
                for the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic` (default), `Cartesian3D`, `Cartesian2D`,
                `XYLine`, `PlotType.Sketch`, `PolarLine`.
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `False`)

            solution_time_source (`VTKLoader.SolutionTimeSource`, optional): Assign
                the solution times of the zones based on the specified criteria.
                Possible values are: `VTKLoader.SolutionTimeSource.Auto` (default)
                which favors the "time" scalar over the numbers embedded in the
                file names, `VTKLoader.SolutionTimeSource.None_` which does not
                assign solutions times or strands,
                `VTKLoader.SolutionTimeSource.FromFieldData` which uses the "time"
                scalar and `VTKLoader.SolutionTimeSource.FromFilename` which uses
                the solution time embedded in the file names.

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``
        """
        if isinstance(solution_time_source, SolutionTimeSource):
            enum_value = solution_time_source.value
            solution_time_source = VTKLoader.SolutionTimeSource(enum_value)
            if __debug__:
                tecutil.api_moved('SolutionTimeSource',
                                  'VTKLoader.SolutionTimeSource',
                                  '1.4', '2021 R1', warning=True)

        if isinstance(filenames, six.string_types):
            filenames = [filenames]
        with StringList('STANDARDSYNTAX', '1.0') as instr:
            with tecutil.ArgList() as arglist:
                arglist[sv.DATASETREADER] = 'VTK Data Loader'
                instr += ['FILELIST_DATAFILES', str(len(filenames))]
                instr += [tecutil.normalize_path(f) for f in filenames]
                instr += ['SOLUTIONTIMESOURCE',
                          VTKLoader.SolutionTimeSource(solution_time_source).value]
                arglist[sv.FILENAMESORINSTRUCTIONS] = instr
                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style, initial_plot_type=initial_plot_type,
                    assign_strand_ids=assign_strand_ids,
                    add_zones_to_existing_strands=add_zones_to_existing_strands)

    @lock()
    def load_tecplot(filenames,

                     frame=None,

                     read_data_option=ReadDataOption.Append,
                     reset_style=None,
                     initial_plot_first_zone_only=None,
                     initial_plot_type=None,

                     zones=None,
                     variables=None,

                     collapse=None,
                     skip=None,
                     assign_strand_ids=True,
                     add_zones_to_existing_strands=None,

                     include_text=None,
                     include_geom=None,
                     include_custom_labels=None,
                     include_data=None):
        """Read a tecplot data file.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): Files to be
                read. (See note below concerning absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        The `DataSet` in the active frame is replaced by the new
                        `DataSet`. If other frames were using the same `DataSet`
                        originally in the active frame, they will continue to use
                        it.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame, and to
                        all other frames that use the same `DataSet`.

                    Default: `ReadDataOption.Append`
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_first_zone_only (`bool`, optional): Informs
                the |Tecplot Engine| that after the data is loaded it only needs to
                activate the first enabled `Zone <data_access>` for the initial
                plot. This option is particularly useful if you have many `Zones
                <data_access>` and want to get the data into the |Tecplot Engine|
                and the first `Zone <data_access>` drawn as fast as possible. The
                inactive `Zones <data_access>` can always be activated when needed.
                (default: `False`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type
                for the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic` (default), `Cartesian3D`, `Cartesian2D`,
                `XYLine`, `PlotType.Sketch`, `PolarLine`.

            zones (`set` of `integers <int>`, optional): Set of `Zones
                <data_access>` to load. Use `None` to load all zones. (default:
                `None`)
            variables (`set` of `strings <str>` or `integers <int>`, optional):
                Set of `Variables <Variable>` to load. Use `None` to load all
                variables. (default: `None`)

            collapse (`bool`, optional): Reindex `Zones <data_access>` and
                `Variables <Variable>` if any are disabled. (default: `False`)
            skip: (3-`tuple` of `integers <int>`, optional) The *ijk*-skip. A value
                of (1,1,1) loads every data point in the *(i,j,k)* directions. A
                value of (2,2,2) loads every other data point and so forth. This
                only applies to ordered data. (default: (1,1,1))
            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `False`)

            include_text (`bool`, optional): Load any text, geometries, or
                custom labels (default: `True`)
            include_geom (`bool`, optional): Load geometries. (default:
                `True`)
            include_custom_labels (`bool`, optional):  (default: `True`)
            include_data (`bool`, optional): Load data. Set this to
                `False` if you only want annotations such as text or geometries.
                (default: `True`)

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        Raises:
            `TecplotSystemError`: Internal error when loading data.
            `TecplotTypeError`: In-valid input.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``
        """
        if isinstance(filenames, six.string_types):
            filenames = [filenames]
        with StringList(tecutil.normalize_path(f) for f in filenames) as fnames:
            with tecutil.ArgList() as arglist:
                allocd = []

                arglist.update(**{
                    sv.DATASETREADER: 'TECPLOT',
                    sv.FILENAMESORINSTRUCTIONS: fnames,
                    sv.INCLUDETEXT: include_text,
                    sv.INCLUDEGEOM: include_geom,
                    sv.INCLUDECUSTOMLABELS: include_custom_labels,
                    sv.INCLUDEDATA: include_data,
                    sv.COLLAPSEZONESANDVARS: collapse})

                if zones is not None:
                    zoneset = IndexSet(zones)
                    allocd.append(zoneset)
                    arglist[sv.ZONELIST] = zoneset

                if variables is None:
                    arglist[sv.VARLOADMODE] = VarLoadMode.ByName

                else:
                    if isinstance(variables[0], int):
                        arglist[sv.VARLOADMODE] = VarLoadMode.ByPosition
                        varset = IndexSet(*variables)
                        allocd.append(varset)
                        arglist[sv.VARPOSITIONLIST] = varset
                    elif isinstance(variables[0], six.string_types):
                        arglist[sv.VARLOADMODE] = VarLoadMode.ByName
                        var_string_list = StringList(*variables)
                        allocd.append(var_string_list)
                        arglist[sv.VARNAMELIST] = var_string_list
                    else:
                        err = 'unknown type for variables: {}'
                        raise TecplotTypeError(err.format(type(variables)))
                if skip is not None:
                    i, j, k = skip
                    arglist[sv.ISKIP] = i
                    arglist[sv.JSKIP] = j
                    arglist[sv.KSKIP] = k

                try:
                    return _tecplot_loader_load_data(
                        arglist, frame=frame, read_data_option=read_data_option,
                        reset_style=reset_style,
                        initial_plot_first_zone_only=initial_plot_first_zone_only,
                        initial_plot_type=initial_plot_type,
                        assign_strand_ids=assign_strand_ids,
                        add_zones_to_existing_strands=add_zones_to_existing_strands)
                finally:
                    for a in allocd:
                        a.dealloc()

    @lock()
    def load_tecplot_szl(filenames,

                         frame=None,

                         read_data_option=ReadDataOption.Append,
                         reset_style=None,
                         initial_plot_first_zone_only=None,
                         initial_plot_type=None,
                         assign_strand_ids=True,
                         add_zones_to_existing_strands=None,

                         server=None,
                         connection_method=None,
                         user=None,
                         authentication_method=None,
                         ssh_private_keyfile=None,
                         szlserver_path=None):
        """Read tecplot SZL data file.

        Parameters:
            filenames (`str` or `list` of `strings <str>`): Files to be
                read. (See note below concerning absolute and relative paths.)
            frame (`Frame`, optional): The `Frame` to attach the resulting
                `Dataset`. If `None`, the currently active `Frame` is used and the
                zones are appended by default.
            read_data_option (`ReadDataOption`, optional): Specify how the data
                is loaded into Tecplot. (default: `ReadDataOption.Append`)

                Possible values are:
                    * `ReadDataOption.ReplaceInActiveFrame`
                        Remove the dataset from the active frame prior to reading
                        in the new dataset. If other frames use the same `DataSet`
                        in the active frame, they will continue to use the old one.
                    * `ReadDataOption.Append`
                        Append to the existing `DataSet`.
                    * `ReadDataOption.Replace`
                        Replace the `DataSet` attached to the active frame and to
                        all other frames that use the same `DataSet`.
            reset_style (`bool`, optional): Reset the style for
                destination `Frame`. If `False`, the `Frame`'s current style is
                preserved. (default: `True`)
            initial_plot_first_zone_only (`bool`, optional): Informs
                the |Tecplot Engine| that after the data is loaded it only needs to
                activate the first enabled `Zone <data_access>` for the initial
                plot. This option is particularly useful if you have many `Zones
                <data_access>` and want to get the data into the |Tecplot Engine|
                and the first `Zone <data_access>` drawn as fast as possible. The
                inactive `Zones <data_access>` can always be activated when needed.
                (default: `False`)
            initial_plot_type (`PlotType`, optional): Forces a specific type of
                plot upon loading of the data. Only used if *resetstyle* is `True`.
                To have |Tecplot 360| determine the most appropriate plot type
                for the data, use `PlotType.Automatic`. Possible values are:
                `PlotType.Automatic` (default), `Cartesian3D`, `Cartesian2D`,
                `XYLine`, `PlotType.Sketch`, `PolarLine`.

            assign_strand_ids (`bool`, optional): Assign strand ID's to
                zones that have a strand ID of -1. (default: `True`)
            add_zones_to_existing_strands (`bool`, optional): Add the
                `Zones <data_access>` to matching strands, if they exist.
                Otherwise, if the new data specifies strands, new ones will be
                created beginning after the last strand in the `Dataset`. (default:
                `False`)

            server (`str`, optional): Load the data remotely from this
                server address. When provided, file paths will be relative to the
                SZL server's working directory. (default: `None`)
            connection_method (`SZLLoader.RemoteConnectionMethod`, optional): When
                *server* is given, this specifies the type of connection to be
                made. Possible values are:
                `SZLLoader.RemoteConnectionMethod.Tunneled` (default),
                `SZLLoader.RemoteConnectionMethod.Direct`,
                `SZLLoader.RemoteConnectionMethod.Manual`.
            user (`str`, optional): When *server* is given and *connection_method*
                is `SZLLoader.RemoteConnectionMethod.Tunneled` or
                `SZLLoader.RemoteConnectionMethod.Direct`, this specifies the
                username to use when logging into the server. This will default to
                the client host's user name.
            authentication_method (`SZLLoader.RemoteAuthenticationMethod`, optional):
                The authentication method to use when connecting to the remote
                server when *connection_method* is
                `SZLLoader.RemoteConnectionMethod.Tunneled` or
                `SZLLoader.RemoteConnectionMethod.Direct`. Possible values are
                `SZLLoader.RemoteAuthenticationMethod.SSHAgent`,
                `SZLLoader.RemoteAuthenticationMethod.SSHPrivateKey` (default)
                which uses the file specified by *ssh_private_keyfile* or
                `SZLLoader.RemoteAuthenticationMethod.Password` which will prompt
                the user for the remote login password in the console.
            ssh_private_keyfile (`str`, optional): When *server* is specified and
                *connection_method* is set to
                `SZLLoader.RemoteConnectionMethod.Tunneled` or
                `SZLLoader.RemoteConnectionMethod.Direct` and when
                *authentication_method* is set to
                `SZLLoader.RemoteAuthenticationMethod.SSHPrivateKey`, this
                specifies the full path to the private SSH keyfile. This parameter
                defaults to ``~/.ssh/id_rsa`` where ``~`` expands out to the local
                user's home directory.

        Returns:
            `Dataset`: The `Dataset` holding the loaded data.

        .. note:: **Absolute and relative paths with PyTecplot**

            Relative paths, when used within the PyTecplot API are always from
            Python's current working directory which can be obtained by calling
            :func:`os.getcwd()`. This is true for batch and `connected
            <tecplot.session.connect()>` modes. One exception to this is paths
            within a macro command or file which will be relative to the |Tecplot
            Engine|'s home directory, which is typically the |Tecplot 360|
            installation directory. Finally, when connected to a remote (non-local)
            instance of Tecplot 360, only absolute paths are allowed.

            Note that backslashes must be escaped which is especially important for
            windows paths such as ``"C:\\\\Users"`` or ``"\\\\\\\\server\\\\path"``
            which will resolve to ``"C:\\Users"`` and ``"\\\\server\\path"``
            respectively. Alternatively, one may use Python's raw strings:
            ``r"C:\\Users"`` and ``r"\\\\server\\path"``

        """
        if isinstance(connection_method, RemoteConnectionMethod):
            enum_value = connection_method.value
            connection_method = SZLLoader.RemoteConnectionMethod(enum_value)
            if __debug__:
                tecutil.api_moved('RemoteConnectionMethod',
                                  'SZLLoader.RemoteConnectionMethod',
                                  '1.4', '2021 R1', warning=True)
        if isinstance(authentication_method, RemoteAuthenticationMethod):
            enum_value = authentication_method.value
            authentication_method = SZLLoader.RemoteAuthenticationMethod(enum_value)
            if __debug__:
                tecutil.api_moved('RemoteAuthenticationMethod',
                                  'SZLLoader.RemoteAuthenticationMethod',
                                  '1.4', '2021 R1', warning=True)

        ConnectionMethod = SZLLoader.RemoteConnectionMethod
        AuthenticationMethod = SZLLoader.RemoteAuthenticationMethod
        if isinstance(filenames, six.string_types):
            filenames = [filenames]
        if server is not None:
            if connection_method is None:
                connection_method = ConnectionMethod.Tunneled
            else:
                connection_method = ConnectionMethod(connection_method)

            if (
                not _tecutil_connector.connected and
                connection_method == ConnectionMethod.Manual
            ):
                msg = 'Manual connection to SZL server not supported in batch mode'
                raise TecplotLogicError(msg)

        with tecutil.ArgList() as arglist:
            if server is None:
                instr = ['STANDARDSYNTAX', '1.0']
                instr += ['FILELIST_DATAFILES', str(len(filenames))]
                instr += [tecutil.normalize_path(f) for f in filenames]

                arglist['DATASETREADER'] = 'Tecplot Subzone Data Loader'
            else:
                if user is None:
                    user = getpass.getuser()

                instr = ['Connection Method', connection_method.value,
                         'MACHINE', server]

                if connection_method in [ConnectionMethod.Tunneled,
                                         ConnectionMethod.Direct]:
                    if authentication_method is None:
                        auth = AuthenticationMethod.SSHPrivateKey
                    else:
                        auth = AuthenticationMethod(authentication_method)

                    instr += ['USER', user, 'SSH Authentication Option', auth.value]

                    if auth == AuthenticationMethod.SSHPrivateKey:
                        if ssh_private_keyfile is None:
                            homedir = os.path.expanduser('~')
                            keyfile = os.path.join(homedir, '.ssh', 'id_rsa')
                        else:
                            keyfile = os.path.expanduser(ssh_private_keyfile)
                        instr += ['Key Path', str(keyfile)]

                    if szlserver_path is not None:
                        instr += ['Server Executable Path', str(szlserver_path)]

                instr += ['FILELIST_DATAFILES', str(len(filenames))]
                instr += filenames

                arglist[sv.DATASETREADER] = 'SZL Remote Loader'

            with tecutil.StringList(*instr) as instr:
                arglist['FILENAMESORINSTRUCTIONS'] = instr
                return _tecplot_loader_load_data(
                    arglist, frame=frame, read_data_option=read_data_option,
                    reset_style=reset_style,
                    initial_plot_first_zone_only=initial_plot_first_zone_only,
                    initial_plot_type=initial_plot_type,
                    assign_strand_ids=assign_strand_ids,
                    add_zones_to_existing_strands=add_zones_to_existing_strands)