"""Lazy-loaded imports from VTK. These are the modules within VTK that must be loaded across pyvista's core and plotting API. The modules are lazily-loaded, and are only imported on first access. We import from ``vtkmodules`` instead of ``vtk`` to selectively import modules and not the entire library. """ from __future__ import annotations import importlib from typing import TYPE_CHECKING if TYPE_CHECKING: from collections.abc import Callable from typing import Any # Type checkers cannot resolve the dynamic lazy vtk imports, so we import everything # here as needed to ensure they can "see" the imported classes from vtk import * # noqa: TID251 from vtkmodules.numpy_interface.dataset_adapter import * # noqa: TID251 from vtkmodules.util.vtkAlgorithm import * # noqa: TID251 # Canonical mapping: vtkmodule -> classes # Modules imported for pyvista's core API _CORE_MODULES: dict[str, tuple[str, ...]] = { 'numpy_interface.dataset_adapter': ( 'VTKArray', 'VTKObjectWrapper', 'numpyTovtkDataArray', ), 'numpy_interface.vtk_aos_array': ('VTKAOSArray',), 'numpy_interface.vtk_implicit_array': ('VTKImplicitArray',), 'util.numpy_support': ( 'get_vtk_array_type', 'numpy_to_vtk', 'numpy_to_vtkIdTypeArray', 'vtk_to_numpy', ), 'util.pickle_support': ('serialize_VTK_data_object',), 'util.vtkAlgorithm': ('VTKPythonAlgorithmBase',), 'vtkCommonComputationalGeometry': ( 'vtkKochanekSpline', 'vtkParametricBohemianDome', 'vtkParametricBour', 'vtkParametricBoy', 'vtkParametricCatalanMinimal', 'vtkParametricConicSpiral', 'vtkParametricCrossCap', 'vtkParametricDini', 'vtkParametricEllipsoid', 'vtkParametricEnneper', 'vtkParametricFigure8Klein', 'vtkParametricFunction', 'vtkParametricHenneberg', 'vtkParametricKlein', 'vtkParametricKuen', 'vtkParametricMobius', 'vtkParametricPluckerConoid', 'vtkParametricPseudosphere', 'vtkParametricRandomHills', 'vtkParametricRoman', 'vtkParametricSpline', 'vtkParametricSuperEllipsoid', 'vtkParametricSuperToroid', 'vtkParametricTorus', ), 'vtkCommonCore': ( 'VTK_ARIAL', 'VTK_COURIER', 'VTK_DOUBLE_MAX', 'VTK_DOUBLE_MIN', 'VTK_FONT_FILE', 'VTK_TIMES', 'VTK_UNSIGNED_CHAR', 'buffer_shared', 'mutable', 'reference', 'vtkAbstractArray', 'vtkBitArray', 'vtkCharArray', 'vtkCommand', 'vtkDataArray', 'vtkDoubleArray', 'vtkFileOutputWindow', 'vtkFloatArray', 'vtkIdList', 'vtkIdTypeArray', 'vtkInformation', 'vtkLogger', 'vtkLookupTable', 'vtkMath', 'vtkObjectBase', 'vtkOutputWindow', 'vtkPoints', 'vtkSMPTools', 'vtkSignedCharArray', 'vtkStringArray', 'vtkStringOutputWindow', 'vtkTypeInt32Array', 'vtkTypeInt64Array', 'vtkTypeUInt32Array', 'vtkUnsignedCharArray', 'vtkVersion', 'vtkWeakReference', ), 'vtkCommonDataModel': ( 'VTK_BEZIER_CURVE', 'VTK_BEZIER_HEXAHEDRON', 'VTK_BEZIER_PYRAMID', 'VTK_BEZIER_QUADRILATERAL', 'VTK_BEZIER_TETRAHEDRON', 'VTK_BEZIER_TRIANGLE', 'VTK_BEZIER_WEDGE', 'VTK_BIQUADRATIC_QUAD', 'VTK_BIQUADRATIC_QUADRATIC_HEXAHEDRON', 'VTK_BIQUADRATIC_QUADRATIC_WEDGE', 'VTK_BIQUADRATIC_TRIANGLE', 'VTK_CONVEX_POINT_SET', 'VTK_CUBIC_LINE', 'VTK_EMPTY_CELL', 'VTK_HEXAGONAL_PRISM', 'VTK_HEXAHEDRON', 'VTK_HIGHER_ORDER_EDGE', 'VTK_HIGHER_ORDER_HEXAHEDRON', 'VTK_HIGHER_ORDER_POLYGON', 'VTK_HIGHER_ORDER_PYRAMID', 'VTK_HIGHER_ORDER_QUAD', 'VTK_HIGHER_ORDER_TETRAHEDRON', 'VTK_HIGHER_ORDER_TRIANGLE', 'VTK_HIGHER_ORDER_WEDGE', 'VTK_LAGRANGE_CURVE', 'VTK_LAGRANGE_HEXAHEDRON', 'VTK_LAGRANGE_PYRAMID', 'VTK_LAGRANGE_QUADRILATERAL', 'VTK_LAGRANGE_TETRAHEDRON', 'VTK_LAGRANGE_TRIANGLE', 'VTK_LAGRANGE_WEDGE', 'VTK_LINE', 'VTK_PARAMETRIC_CURVE', 'VTK_PARAMETRIC_HEX_REGION', 'VTK_PARAMETRIC_QUAD_SURFACE', 'VTK_PARAMETRIC_SURFACE', 'VTK_PARAMETRIC_TETRA_REGION', 'VTK_PARAMETRIC_TRI_SURFACE', 'VTK_PENTAGONAL_PRISM', 'VTK_PIXEL', 'VTK_POLY_LINE', 'VTK_POLY_VERTEX', 'VTK_POLYGON', 'VTK_POLYHEDRON', 'VTK_PYRAMID', 'VTK_QUAD', 'VTK_QUADRATIC_EDGE', 'VTK_QUADRATIC_HEXAHEDRON', 'VTK_QUADRATIC_LINEAR_QUAD', 'VTK_QUADRATIC_LINEAR_WEDGE', 'VTK_QUADRATIC_POLYGON', 'VTK_QUADRATIC_PYRAMID', 'VTK_QUADRATIC_QUAD', 'VTK_QUADRATIC_TETRA', 'VTK_QUADRATIC_TRIANGLE', 'VTK_QUADRATIC_WEDGE', 'VTK_TETRA', 'VTK_TRIANGLE', 'VTK_TRIANGLE_STRIP', 'VTK_TRIQUADRATIC_HEXAHEDRON', 'VTK_TRIQUADRATIC_PYRAMID', 'VTK_VERTEX', 'VTK_VOXEL', 'VTK_WEDGE', 'vtkAbstractCellLocator', 'vtkBezierCurve', 'vtkBezierHexahedron', 'vtkBezierQuadrilateral', 'vtkBezierTetra', 'vtkBezierTriangle', 'vtkBezierWedge', 'vtkBiQuadraticQuad', 'vtkBiQuadraticQuadraticHexahedron', 'vtkBiQuadraticQuadraticWedge', 'vtkBiQuadraticTriangle', 'vtkCell', 'vtkCellArray', 'vtkCellLocator', 'vtkCellStatus', 'vtkCellTreeLocator', 'vtkCellTypes', 'vtkColor3ub', 'vtkCompositeDataSet', 'vtkConvexPointSet', 'vtkCubicLine', 'vtkDataObject', 'vtkDataSet', 'vtkDataSetAttributes', 'vtkEmptyCell', 'vtkExplicitStructuredGrid', 'vtkFieldData', 'vtkGenericCell', 'vtkHexagonalPrism', 'vtkHexahedron', 'vtkImageData', 'vtkImplicitBoolean', 'vtkImplicitFunction', 'vtkIterativeClosestPointTransform', 'vtkLagrangeCurve', 'vtkLagrangeHexahedron', 'vtkLagrangeQuadrilateral', 'vtkLagrangeTetra', 'vtkLagrangeTriangle', 'vtkLagrangeWedge', 'vtkLine', 'vtkMultiBlockDataSet', 'vtkNonMergingPointLocator', 'vtkPartitionedDataSet', 'vtkPentagonalPrism', 'vtkPerlinNoise', 'vtkPiecewiseFunction', 'vtkPixel', 'vtkPlane', 'vtkPlaneCollection', 'vtkPlanes', 'vtkPointLocator', 'vtkPointSet', 'vtkPolyData', 'vtkPolygon', 'vtkPolyhedron', 'vtkPolyLine', 'vtkPolyPlane', 'vtkPolyVertex', 'vtkPyramid', 'vtkQuad', 'vtkQuadraticEdge', 'vtkQuadraticHexahedron', 'vtkQuadraticLinearQuad', 'vtkQuadraticLinearWedge', 'vtkQuadraticPolygon', 'vtkQuadraticPyramid', 'vtkQuadraticQuad', 'vtkQuadraticTetra', 'vtkQuadraticTriangle', 'vtkQuadraticWedge', 'vtkRectf', 'vtkRectilinearGrid', 'vtkSelection', 'vtkSelectionNode', 'vtkStaticCellLocator', 'vtkStaticPointLocator', 'vtkStructuredGrid', 'vtkStructuredPoints', 'vtkTable', 'vtkTetra', 'vtkTriangle', 'vtkTriangleStrip', 'vtkTriQuadraticHexahedron', 'vtkTriQuadraticPyramid', 'vtkUnstructuredGrid', 'vtkVertex', 'vtkVoxel', 'vtkWedge', ), 'vtkCommonExecutionModel': ( 'vtkAlgorithm', 'vtkAlgorithmOutput', 'vtkCompositeDataPipeline', 'vtkImageToStructuredGrid', ), 'vtkCommonMath': ( 'vtkMatrix3x3', 'vtkMatrix4x4', ), 'vtkCommonTransforms': ('vtkTransform',), 'vtkDomainsChemistry': ('vtkProteinRibbonFilter',), 'vtkFiltersCore': ( 'VTK_BEST_FITTING_PLANE', 'vtkAppendArcLength', 'vtkAppendFilter', 'vtkAppendPolyData', 'vtkCellCenters', 'vtkCellDataToPointData', 'vtkCenterOfMass', 'vtkCleanPolyData', 'vtkClipPolyData', 'vtkConnectivityFilter', 'vtkContourFilter', 'vtkConvertToMultiBlockDataSet', 'vtkCutter', 'vtkDecimatePolylineFilter', 'vtkDecimatePro', 'vtkDelaunay2D', 'vtkDelaunay3D', 'vtkElevationFilter', 'vtkExplicitStructuredGridToUnstructuredGrid', 'vtkExtractEdges', 'vtkFeatureEdges', 'vtkFlyingEdges3D', 'vtkGlyph3D', 'vtkImageAppend', 'vtkImplicitPolyDataDistance', 'vtkMarchingCubes', 'vtkMassProperties', 'vtkMergeFilter', 'vtkOrientPolyData', 'vtkPackLabels', 'vtkPointDataToCellData', 'vtkPolyDataNormals', 'vtkQuadricDecimation', 'vtkResampleWithDataSet', 'vtkReverseSense', 'vtkSmoothPolyDataFilter', 'vtkStaticCleanUnstructuredGrid', 'vtkStripper', 'vtkSurfaceNets3D', 'vtkThreshold', 'vtkTriangleFilter', 'vtkTubeFilter', 'vtkUnstructuredGridToExplicitStructuredGrid', 'vtkWindowedSincPolyDataFilter', ), 'vtkFiltersExtraction': ( 'vtkExtractCellsByType', 'vtkExtractGeometry', 'vtkExtractGrid', 'vtkExtractSelection', ), 'vtkFiltersFlowPaths': ( 'vtkEvenlySpacedStreamlines2D', 'vtkStreamTracer', ), 'vtkFiltersGeneral': ( 'vtkAxes', 'vtkBooleanOperationPolyDataFilter', 'vtkBoxClipDataSet', 'vtkCellValidator', 'vtkClipClosedSurface', 'vtkContourTriangulator', 'vtkCursor3D', 'vtkCurvatures', 'vtkDataSetTriangleFilter', 'vtkGradientFilter', 'vtkIntersectionPolyDataFilter', 'vtkOBBTree', 'vtkRectilinearGridToPointSet', 'vtkRectilinearGridToTetrahedra', 'vtkRemovePolyData', 'vtkShrinkFilter', 'vtkTableBasedClipDataSet', 'vtkTableToPolyData', 'vtkTessellatorFilter', 'vtkTransformFilter', 'vtkWarpScalar', 'vtkWarpVector', ), 'vtkFiltersGeometry': ( 'vtkCompositeDataGeometryFilter', 'vtkDataSetSurfaceFilter', 'vtkGeometryFilter', 'vtkStructuredGridGeometryFilter', ), 'vtkFiltersHybrid': ('vtkPolyDataSilhouette',), 'vtkFiltersModeling': ( 'vtkAdaptiveSubdivisionFilter', 'vtkBandedPolyDataContourFilter', 'vtkButterflySubdivisionFilter', 'vtkCollisionDetectionFilter', 'vtkDijkstraGraphGeodesicPath', 'vtkFillHolesFilter', 'vtkLinearExtrusionFilter', 'vtkLinearSubdivisionFilter', 'vtkLoopSubdivisionFilter', 'vtkOutlineFilter', 'vtkRibbonFilter', 'vtkRotationalExtrusionFilter', 'vtkRuledSurfaceFilter', 'vtkSelectEnclosedPoints', 'vtkSubdivideTetra', 'vtkTrimmedExtrusionFilter', ), 'vtkFiltersParallel': ('vtkIntegrateAttributes',), 'vtkFiltersParallelDIY2': ('vtkRedistributeDataSetFilter',), 'vtkFiltersPoints': ( 'vtkConvertToPointCloud', 'vtkGaussianKernel', 'vtkPointInterpolator', ), 'vtkFiltersSources': ( 'vtkArcSource', 'vtkArrowSource', 'vtkCapsuleSource', # Deprecated 9.3.0 'vtkCellTypeSource', 'vtkConeSource', 'vtkCubeSource', 'vtkCylinderSource', 'vtkDiskSource', 'vtkFrustumSource', 'vtkLineSource', 'vtkOutlineCornerFilter', 'vtkOutlineCornerSource', 'vtkParametricFunctionSource', 'vtkPlaneSource', 'vtkPlatonicSolidSource', 'vtkPointSource', 'vtkRegularPolygonSource', 'vtkSphereSource', 'vtkSuperquadricSource', 'vtkTessellatedBoxSource', ), 'vtkFiltersStatistics': ( 'vtkComputeQuartiles', 'vtkLengthDistribution', ), 'vtkFiltersTexture': ( 'vtkTextureMapToPlane', 'vtkTextureMapToSphere', ), 'vtkFiltersVerdict': ( 'vtkBoundaryMeshQuality', 'vtkCellQuality', 'vtkCellSizeFilter', 'vtkMeshQuality', ), 'vtkImagingCore': ( 'vtkAbstractImageInterpolator', 'vtkExtractVOI', 'vtkImageBinaryThreshold', 'vtkImageBSplineCoefficients', 'vtkImageBSplineInterpolator', 'vtkImageConstantPad', 'vtkImageDifference', 'vtkImageExtractComponents', 'vtkImageFlip', 'vtkImageInterpolator', 'vtkImageMirrorPad', 'vtkImageResize', 'vtkImageSincInterpolator', 'vtkImageThreshold', 'vtkImageWrapPad', 'vtkRTAnalyticSource', ), 'vtkImagingFourier': ( 'vtkImageButterworthHighPass', 'vtkImageButterworthLowPass', 'vtkImageFFT', 'vtkImageRFFT', ), 'vtkImagingGeneral': ( 'vtkImageGaussianSmooth', 'vtkImageMedian3D', ), 'vtkImagingHybrid': ( 'vtkGaussianSplatter', 'vtkSampleFunction', 'vtkSurfaceReconstructionFilter', ), 'vtkImagingMorphological': ( 'vtkImageConnectivityFilter', 'vtkImageContinuousDilate3D', 'vtkImageContinuousErode3D', 'vtkImageDilateErode3D', ), 'vtkImagingSources': ( 'vtkImageEllipsoidSource', 'vtkImageGaussianSource', 'vtkImageGridSource', 'vtkImageMandelbrotSource', 'vtkImageNoiseSource', 'vtkImageSinusoidSource', ), 'vtkImagingStencil': ( 'vtkImageStencil', 'vtkPolyDataToImageStencil', ), 'vtkIOExodus': ('vtkExodusIIReader',), 'vtkIOExport': ( 'vtkGLTFExporter', 'vtkOBJExporter', 'vtkVRMLExporter', ), 'vtkIOExportGL2PS': ('vtkGL2PSExporter',), 'vtkIOImport': ( 'vtk3DSImporter', 'vtkGLTFImporter', 'vtkOBJImporter', 'vtkVRMLImporter', ), 'vtkIOInfovis': ('vtkDelimitedTextReader',), 'vtkIOLegacy': ( 'vtkDataSetReader', 'vtkDataSetWriter', 'vtkDataWriter', ), 'vtkIOXML': ( 'vtkXMLImageDataReader', 'vtkXMLImageDataWriter', 'vtkXMLPolyDataReader', 'vtkXMLPolyDataWriter', 'vtkXMLRectilinearGridReader', 'vtkXMLRectilinearGridWriter', 'vtkXMLStructuredGridReader', 'vtkXMLStructuredGridWriter', 'vtkXMLTableReader', 'vtkXMLTableWriter', 'vtkXMLUnstructuredGridReader', 'vtkXMLUnstructuredGridWriter', ), } # Rendering modules for pyvista's plotting API _PLOTTING_MODULES: dict[str, tuple[str, ...]] = { 'vtkChartsCore': ( 'vtkAxis', 'vtkChart', 'vtkChartBox', 'vtkChartPie', 'vtkChartXY', 'vtkChartXYZ', 'vtkPlotArea', 'vtkPlotBar', 'vtkPlotBox', 'vtkPlotLine', 'vtkPlotLine3D', 'vtkPlotPie', 'vtkPlotPoints', 'vtkPlotPoints3D', 'vtkPlotStacked', 'vtkPlotSurface', ), 'vtkCommonColor': ( 'vtkColorSeries', 'vtkNamedColors', ), 'vtkInteractionStyle': ( 'vtkInteractorStyleImage', 'vtkInteractorStyleJoystickActor', 'vtkInteractorStyleJoystickCamera', 'vtkInteractorStyleRubberBand2D', 'vtkInteractorStyleRubberBandPick', 'vtkInteractorStyleRubberBandZoom', 'vtkInteractorStyleTerrain', 'vtkInteractorStyleTrackballActor', 'vtkInteractorStyleTrackballCamera', ), 'vtkInteractionWidgets': ( 'vtkBoxWidget', 'vtkButtonWidget', 'vtkCamera3DRepresentation', 'vtkCamera3DWidget', 'vtkCameraOrientationWidget', 'vtkDistanceRepresentation3D', 'vtkDistanceWidget', 'vtkImplicitPlaneWidget', 'vtkLineWidget', 'vtkLogoRepresentation', 'vtkLogoWidget', 'vtkOrientationMarkerWidget', 'vtkPlaneWidget', 'vtkPointHandleRepresentation3D', 'vtkResliceCursorPicker', 'vtkScalarBarWidget', 'vtkSliderRepresentation2D', 'vtkSliderWidget', 'vtkSphereWidget', 'vtkSplineWidget', 'vtkTexturedButtonRepresentation2D', ), 'vtkRenderingAnnotation': ( 'vtkAnnotatedCubeActor', 'vtkAxesActor', 'vtkAxisActor', 'vtkAxisActor2D', 'vtkCornerAnnotation', 'vtkCubeAxesActor', 'vtkLegendBoxActor', 'vtkLegendScaleActor', 'vtkScalarBarActor', ), 'vtkRenderingContext2D': ( 'vtkBlockItem', 'vtkBrush', 'vtkContext2D', 'vtkContextActor', 'vtkContextScene', 'vtkImageItem', 'vtkPen', ), 'vtkRenderingCore': ( 'VTK_RESOLVE_OFF', 'VTK_RESOLVE_POLYGON_OFFSET', 'VTK_RESOLVE_SHIFT_ZBUFFER', 'vtkAbstractMapper', 'vtkActor', 'vtkActor2D', 'vtkAreaPicker', 'vtkCamera', 'vtkCellPicker', 'vtkColorTransferFunction', 'vtkCompositeDataDisplayAttributes', 'vtkCompositePolyDataMapper', 'vtkCoordinate', 'vtkDataSetMapper', 'vtkFollower', 'vtkHardwarePicker', 'vtkImageActor', 'vtkInteractorStyle', 'vtkLight', 'vtkLightActor', 'vtkLightKit', 'vtkMapper', 'vtkPointGaussianMapper', 'vtkPointPicker', 'vtkPolyDataMapper', 'vtkPolyDataMapper2D', 'vtkProp', 'vtkProp3D', 'vtkPropAssembly', 'vtkPropCollection', 'vtkProperty', 'vtkPropPicker', 'vtkRenderedAreaPicker', 'vtkRenderer', 'vtkRenderWindow', 'vtkRenderWindowInteractor', 'vtkScenePicker', 'vtkSelectVisiblePoints', 'vtkSkybox', 'vtkTextActor', 'vtkTextProperty', 'vtkTexture', 'vtkViewport', 'vtkVolume', 'vtkVolumeProperty', 'vtkWindowToImageFilter', 'vtkWorldPointPicker', ), 'vtkRenderingFreeType': ( 'vtkMathTextFreeTypeTextRenderer', 'vtkVectorText', ), 'vtkRenderingLabel': ( 'vtkLabelPlacementMapper', 'vtkPointSetToLabelHierarchy', ), 'vtkRenderingUI': ('vtkGenericRenderWindowInteractor',), 'vtkRenderingVolume': ( 'vtkFixedPointVolumeRayCastMapper', 'vtkGPUVolumeRayCastMapper', 'vtkUnstructuredGridVolumeRayCastMapper', 'vtkVolumeMapper', 'vtkVolumePicker', ), 'vtkViewsContext2D': ('vtkContextInteractorStyle',), } # GL-dependent imports from VTK. # These are the modules within VTK requiring libGL that must be loaded # across pyvista's plotting API. These imports have the potential to # raise an ImportError if the user does not have libGL installed. # # ImportError: libGL.so.1: cannot open shared object file: No such file or directory _OPENGL_MODULES: dict[str, tuple[str, ...]] = { 'vtkRenderingOpenGL2': ( 'vtkCameraPass', 'vtkCompositePolyDataMapper2', # optional (contextlib.suppress) 'vtkDepthOfFieldPass', 'vtkEDLShading', 'vtkGaussianBlurPass', 'vtkOpenGLFXAAPass', 'vtkOpenGLHardwareSelector', 'vtkOpenGLRenderer', 'vtkOpenGLSkybox', 'vtkOpenGLTexture', 'vtkRenderPassCollection', 'vtkRenderStepsPass', 'vtkSequencePass', 'vtkShader', 'vtkShadowMapPass', 'vtkSSAAPass', 'vtkSSAOPass', ), 'vtkRenderingVolumeOpenGL2': ( 'vtkOpenGLGPUVolumeRayCastMapper', 'vtkSmartVolumeMapper', ), } # Derived mapping: class -> module _VTK_CLASS_TO_MODULE: dict[str, str] = { cls: module for module, classes in (_CORE_MODULES | _PLOTTING_MODULES | _OPENGL_MODULES).items() for cls in classes } def __getattr__(name: str): """Lazy attribute access. VTK modules are only imported when first accessed. """ # Handle special cases if importer := _SPECIAL_LOADERS.get(name): obj = importer() else: # Default case: lazily import based on module mapping module_name = _VTK_CLASS_TO_MODULE.get(name) if module_name is None: msg = ( f"{name!r} is not defined in PyVista's vtk namespace.\n" f'Developers should add a new `module:{name}` mapping to the `_vtk` module.' ) raise AttributeError(msg) # Attempt to import the vtkmodule and the desired attribute # Convert module or attribute errors into a similar message that would otherwise be # seen when doing `from vtkmodules.vtkModule import vtkClass` module_full_name = f'vtkmodules.{module_name}' error_msg = ( f'Cannot import name {name!r} from {module_full_name!r}.\n' 'The cause is likely attributable to VTK version or a custom VTK build.' ) try: module = importlib.import_module(module_full_name) except ModuleNotFoundError as e: raise ImportError(error_msg) from e try: obj = getattr(module, name) except AttributeError as e: raise ImportError(error_msg) from e # Cache object for next access globals()[name] = obj return obj def has_attr(name: str) -> bool: """Return ``True`` if *name* resolves to a VTK class on this build. ``hasattr(_vtk, 'X')`` does not work as expected because the lazy ``__getattr__`` raises ``ImportError`` (not ``AttributeError``) when a class is mapped but missing from the underlying ``vtkmodules`` module on the installed VTK build. ``hasattr`` only catches ``AttributeError``, so the raised ``ImportError`` propagates and breaks version-probe call sites. Use this helper instead. Parameters ---------- name : str Attribute name to probe on the ``_vtk`` namespace. Returns ------- bool ``True`` if the attribute resolves on this VTK build, ``False`` if it is missing or its underlying ``vtkmodules`` module is missing. """ if name in globals(): return True try: __getattr__(name) except (AttributeError, ImportError): return False return True # Specialized loading functions for irregular imports def _import_vtkPythonItem(): # noqa: N802 try: from vtkmodules.vtkPythonContext2D import vtkPythonItem # noqa: TID251 except ImportError: # pragma: no cover # Suppress for ParaView shell https://github.com/pyvista/pyvista/issues/3224 class vtkPythonItem: # type: ignore[no-redef] # noqa: N801 """Empty placeholder.""" def __init__(self) -> None: # pragma: no cover """Raise version error on init.""" from pyvista.core.errors import VTKVersionError msg = 'Chart backgrounds require the vtkPythonContext2D module' raise VTKVersionError(msg) return vtkPythonItem def _import_vtkExtractCells(): # noqa: N802 try: # Module changed in VTK 9.3.0 from vtkmodules.vtkFiltersCore import vtkExtractCells # noqa: TID251 except ImportError: from vtkmodules.vtkFiltersExtraction import ( # type: ignore[attr-defined, no-redef] # noqa: TID251 vtkExtractCells, ) return vtkExtractCells def _import_vtkCellTypeUtilities(): # noqa: N802 try: # Introduced VTK 9.6.0 from vtkmodules.vtkCommonDataModel import vtkCellTypeUtilities # noqa: TID251 except ImportError: from vtkmodules.vtkCommonDataModel import ( # type:ignore[assignment] # noqa: TID251 vtkCellTypes as vtkCellTypeUtilities, ) return vtkCellTypeUtilities _SPECIAL_LOADERS: dict[str, Callable[[], type[Any]]] = { 'vtkPythonItem': _import_vtkPythonItem, 'vtkExtractCells': _import_vtkExtractCells, 'vtkCellTypeUtilities': _import_vtkCellTypeUtilities, }