|
|
"""Base class for preprocessors""" |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
from traitlets import Bool |
|
|
|
|
|
from nbconvert.utils.base import NbConvertBase |
|
|
|
|
|
|
|
|
class Preprocessor(NbConvertBase): |
|
|
"""A configurable preprocessor |
|
|
|
|
|
Inherit from this class if you wish to have configurability for your |
|
|
preprocessor. |
|
|
|
|
|
Any configurable traitlets this class exposed will be configurable in |
|
|
profiles using c.SubClassName.attribute = value |
|
|
|
|
|
You can overwrite `preprocess_cell()` to apply a transformation |
|
|
independently on each cell or `preprocess()` if you prefer your own |
|
|
logic. See corresponding docstring for information. |
|
|
|
|
|
Disabled by default and can be enabled via the config by |
|
|
'c.YourPreprocessorName.enabled = True' |
|
|
""" |
|
|
|
|
|
enabled = Bool(False).tag(config=True) |
|
|
|
|
|
def __init__(self, **kw): |
|
|
""" |
|
|
Public constructor |
|
|
|
|
|
Parameters |
|
|
---------- |
|
|
config : Config |
|
|
Configuration file structure |
|
|
`**kw` |
|
|
Additional keyword arguments passed to parent |
|
|
""" |
|
|
|
|
|
super().__init__(**kw) |
|
|
|
|
|
def __call__(self, nb, resources): |
|
|
"""Apply the preprocessor.""" |
|
|
if self.enabled: |
|
|
self.log.debug("Applying preprocessor: %s", self.__class__.__name__) |
|
|
return self.preprocess(nb, resources) |
|
|
return nb, resources |
|
|
|
|
|
def preprocess(self, nb, resources): |
|
|
""" |
|
|
Preprocessing to apply on each notebook. |
|
|
|
|
|
Must return modified nb, resources. |
|
|
|
|
|
If you wish to apply your preprocessing to each cell, you might want |
|
|
to override preprocess_cell method instead. |
|
|
|
|
|
Parameters |
|
|
---------- |
|
|
nb : NotebookNode |
|
|
Notebook being converted |
|
|
resources : dictionary |
|
|
Additional resources used in the conversion process. Allows |
|
|
preprocessors to pass variables into the Jinja engine. |
|
|
""" |
|
|
for index, cell in enumerate(nb.cells): |
|
|
nb.cells[index], resources = self.preprocess_cell(cell, resources, index) |
|
|
return nb, resources |
|
|
|
|
|
def preprocess_cell(self, cell, resources, index): |
|
|
""" |
|
|
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 |
|
|
""" |
|
|
msg = "should be implemented by subclass" |
|
|
raise NotImplementedError(msg) |
|
|
|
