Simplify setting of jupyter backend

Signed-off-by: Johannes Mueller <[email protected]>

docs/conf.py

@@ -49,33 +49,14 @@
         ep.preprocess(nb, {'metadata': {'path': os.path.dirname(fn)}})
 
 
-# Inject code to set pyvista jupyter backend into relevant notebooks
-#
-import nbsphinx
-original_from_notebook_node = nbsphinx.Exporter.from_notebook_node
-
-from nbconvert.preprocessors import Preprocessor
-
-def from_notebook_node(self, nb, resources, **kwargs):
-
-    class InjectPyvistaBackendPreprocessor(Preprocessor):
-        def preprocess(self, nb, resources):
-            for index, cell in enumerate(nb.cells):
-                if cell['cell_type'] == 'code' and 'import pyvista as pv' in cell['source'] :
-                    cell['source'] += "\npv.set_jupyter_backend('html')\n"
-                    break
-            return nb, resources
-
-    nb, resources = InjectPyvistaBackendPreprocessor().preprocess(nb, resources=resources)
-    return original_from_notebook_node(self, nb, resources, **kwargs)
-
-nbsphinx.Exporter.from_notebook_node = from_notebook_node
 
 
 # Don't try to use C-code for the pytensor stuff when building the docs.
 # Otherwise the demo notebooks fail on readthedocs
 os.environ['PYTHONWARNINGS'] = 'ignore'
 
+os.environ["PYVISTA_JUPYTER_BACKEND"] = 'html'
+
 import asyncio
 
 # See https://bugs.python.org/issue37373 :(