Source code for bokeh.application.handlers.notebook

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# Copyright (c) 2012 - 2020, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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''' Provide a Bokeh Application Handler to build up documents by running
the code from Jupyter notebook (``.ipynb``) files.

This handler is configured with the filename of a Jupyter notebook. When a
Bokeh application calls ``modify_doc``, the code from all the notebook cells
is collected and executed to process a new Document for a session. When the
notebook code is executed, the Document being modified will be available as
``curdoc``, and any optionally provided ``args`` will be available as
``sys.argv``.

'''

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# Boilerplate
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import logging # isort:skip
log = logging.getLogger(__name__)

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# Imports
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# Standard library imports
import io
import re

# Bokeh imports
from ...util.dependencies import import_required
from .code import CodeHandler

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# Globals and constants
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__all__ = (
    'NotebookHandler',
)

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# General API
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# Dev API
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[docs]class NotebookHandler(CodeHandler): ''' A Handler that uses code in a Jupyter notebook for modifying Bokeh Documents. ''' _logger_text = "%s: call to %s() ignored when running notebooks with the 'bokeh' command." _origin = "Notebook"
[docs] def __init__(self, *args, **kwargs): ''' Keywords: filename (str) : a path to a Jupyter notebook (".ipynb") file ''' nbformat = import_required('nbformat', 'The Bokeh notebook application handler requires Jupyter Notebook to be installed.') nbconvert = import_required('nbconvert', 'The Bokeh notebook application handler requires Jupyter Notebook to be installed.') if 'filename' not in kwargs: raise ValueError('Must pass a filename to NotebookHandler') class StripMagicsProcessor(nbconvert.preprocessors.Preprocessor): """ Preprocessor to convert notebooks to Python source while stripping out all magics (i.e IPython specific syntax). """ _magic_pattern = re.compile(r'^\s*(?P<magic>%%\w\w+)($|(\s+))') def strip_magics(self, source): """ Given the source of a cell, filter out all cell and line magics. """ filtered=[] for line in source.splitlines(): match = self._magic_pattern.match(line) if match is None: filtered.append(line) else: msg = 'Stripping out IPython magic {magic} in code cell {cell}' message = msg.format(cell=self._cell_counter, magic=match.group('magic')) log.warning(message) return '\n'.join(filtered) def preprocess_cell(self, cell, resources, index): if cell['cell_type'] == 'code': self._cell_counter += 1 cell['source'] = self.strip_magics(cell['source']) return cell, resources def __call__(self, nb, resources): self._cell_counter = 0 return self.preprocess(nb,resources) preprocessors=[StripMagicsProcessor()] filename = kwargs['filename'] with io.open(filename, encoding="utf-8") as f: nb = nbformat.read(f, nbformat.NO_CONVERT) exporter = nbconvert.PythonExporter() for preprocessor in preprocessors: exporter.register_preprocessor(preprocessor) source, _ = exporter.from_notebook_node(nb) source = source.replace('get_ipython().run_line_magic', '') source = source.replace('get_ipython().magic', '') kwargs['source'] = source super().__init__(*args, **kwargs)
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