diff --git a/nbconvert/preprocessors/execute.py b/nbconvert/preprocessors/execute.py
index 89b7f6cc5..9946c03b9 100644
--- a/nbconvert/preprocessors/execute.py
+++ b/nbconvert/preprocessors/execute.py
@@ -3,7 +3,10 @@
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
+from typing import Optional
+from nbformat import NotebookNode
from nbclient import NotebookClient, execute as _execute
+from nbclient.util import run_sync
# Backwards compatability for imported name
from nbclient.exceptions import CellExecutionError
@@ -31,12 +34,27 @@ def __init__(self, **kw):
Preprocessor.__init__(self, nb=nb, **kw)
NotebookClient.__init__(self, nb, **kw)
+ def _check_assign_resources(self, resources):
+ if resources or not hasattr(self, 'resources'):
+ self.resources = resources
+
def preprocess(self, nb, resources=None, km=None):
"""
Preprocess notebook executing each code cell.
The input argument *nb* is modified in-place.
+ Note that this function recalls NotebookClient.__init__, which may look wrong.
+ However since the preprocess call acts line an init on exeuction state it's expected.
+ Therefore, we need to capture it here again to properly reset because traitlet
+ assignments are not passed. There is a risk if traitlets apply any side effects for
+ dual init.
+ The risk should be manageable, and this approach minimizes side-effects relative
+ to other alternatives.
+
+ One alternative but rejected implementation would be to copy the client's init internals
+ which has already gotten out of sync with nbclient 0.5 release before nbcovnert 6.0 released.
+
Parameters
----------
nb : NotebookNode
@@ -56,11 +74,73 @@ def preprocess(self, nb, resources=None, km=None):
resources : dictionary
Additional resources used in the conversion process.
"""
- # Copied from NotebookClient init :/
- self.nb = nb
- self.km = km
- if resources:
- self.resources = resources
- self.reset_execution_trackers()
+ NotebookClient.__init__(self, nb, km)
+ self._check_assign_resources(resources)
self.execute()
- return nb, resources
+ return self.nb, self.resources
+
+ async def async_execute_cell(
+ self,
+ cell: NotebookNode,
+ cell_index: int,
+ execution_count: Optional[int] = None,
+ store_history: bool = False) -> NotebookNode:
+ """
+ Executes a single code cell.
+
+ Overwrites NotebookClient's version of this method to allow for preprocess_cell calls.
+
+ Parameters
+ ----------
+ cell : nbformat.NotebookNode
+ The cell which is currently being processed.
+ cell_index : int
+ The position of the cell within the notebook object.
+ execution_count : int
+ The execution count to be assigned to the cell (default: Use kernel response)
+ store_history : bool
+ Determines if history should be stored in the kernel (default: False).
+ Specific to ipython kernels, which can store command histories.
+
+ Returns
+ -------
+ output : dict
+ The execution output payload (or None for no output).
+
+ Raises
+ ------
+ CellExecutionError
+ If execution failed and should raise an exception, this will be raised
+ with defaults about the failure.
+
+ Returns
+ -------
+ cell : NotebookNode
+ The cell which was just processed.
+ """
+ # Copied and intercepted to allow for custom preprocess_cell contracts to be fullfilled
+ self.store_history = store_history
+ cell, resources = self.preprocess_cell(cell, self.resources, cell_index)
+ if execution_count:
+ cell['execution_count'] = execution_count
+ return cell, resources
+
+ def preprocess_cell(self, cell, resources, index, **kwargs):
+ """
+ Override if you want to apply some preprocessing to each cell.
+ Must return modified cell and resource dictionary.
+
+ Parameters
+ ----------
+ cell : NotebookNode cell
+ Notebook cell being processed
+ resources : dictionary
+ Additional resources used in the conversion process. Allows
+ preprocessors to pass variables into the Jinja engine.
+ index : int
+ Index of the cell being processed
+ """
+ self._check_assign_resources(resources)
+ # Because nbclient is an async library, we need to wrap the parent async call to generate a syncronous version.
+ cell = run_sync(NotebookClient.async_execute_cell)(self, cell, index, store_history=self.store_history)
+ return cell, self.resources
diff --git a/nbconvert/preprocessors/tests/test_execute.py b/nbconvert/preprocessors/tests/test_execute.py
index 483e91daf..5b41159cf 100644
--- a/nbconvert/preprocessors/tests/test_execute.py
+++ b/nbconvert/preprocessors/tests/test_execute.py
@@ -11,6 +11,8 @@
import pytest
import nbformat
+from copy import deepcopy
+
from ..execute import ExecutePreprocessor, executenb
@@ -58,19 +60,41 @@ def test_basic_execution():
fname = os.path.join(os.path.dirname(__file__), 'files', 'HelloWorld.ipynb')
with open(fname) as f:
input_nb = nbformat.read(f, 4)
- output_nb, _ = preprocessor.preprocess(input_nb)
+ output_nb, _ = preprocessor.preprocess(deepcopy(input_nb))
assert_notebooks_equal(input_nb, output_nb)
+
def test_executenb():
fname = os.path.join(os.path.dirname(__file__), 'files', 'HelloWorld.ipynb')
with open(fname) as f:
input_nb = nbformat.read(f, 4)
with pytest.warns(FutureWarning):
- output_nb = executenb(input_nb)
+ output_nb = executenb(deepcopy(input_nb))
assert_notebooks_equal(input_nb, output_nb)
+
def test_populate_language_info():
preprocessor = ExecutePreprocessor(kernel_name="python")
nb = nbformat.v4.new_notebook() # Certainly has no language_info.
- nb, _ = preprocessor.preprocess(nb, resources={})
+ preprocessor.preprocess(nb, resources={})
+ # Should mutate input
assert 'language_info' in nb.metadata # See that a basic attribute is filled in
+
+
+def test_preprocess_cell():
+ class CellReplacer(ExecutePreprocessor):
+ def preprocess_cell(self, cell, resources, index, **kwargs):
+ cell.source = "print('Ignored')"
+ return super().preprocess_cell(cell, resources, index, **kwargs)
+
+ preprocessor = CellReplacer()
+ fname = os.path.join(os.path.dirname(__file__), 'files', 'HelloWorld.ipynb')
+ with open(fname) as f:
+ input_nb = nbformat.read(f, 4)
+ output_nb, _ = preprocessor.preprocess(deepcopy(input_nb))
+ expected_nb = deepcopy(input_nb)
+ for cell in expected_nb.cells:
+ cell.source = "print('Ignored')"
+ for output in cell.outputs:
+ output.text = 'Ignored\n'
+ assert_notebooks_equal(expected_nb, output_nb)