Removing cells, inputs, or outputs

When converting Notebooks into other formats, it is possible to remove parts of a cell, or entire cells, using preprocessors. The notebook will remain unchanged, but the outputs will have certain pieces removed. Here are two primary ways to accomplish this.

Removing pieces of cells using cell tags

The most straightforward way to control which pieces of cells are removed is to use cell tags. These are single-string snippets of metadata that are stored in each cells “tag” field. The TagRemovePreprocessor can be used to remove inputs, outputs, or entire cells.

For example, here is a configuration that uses a different tag for removing each part of a cell with the HTMLExporter. In this case, we demonstrate using the nbconvert Python API.

from traitlets.config import Config
import nbformat as nbf
from nbconvert.exporters import HTMLExporter
from nbconvert.preprocessors import TagRemovePreprocessor

# Setup config
c = Config()

# Configure tag removal - be sure to tag your cells to remove  using the
# words remove_cell to remove cells. You can also modify the code to use
# a different tag word
c.TagRemovePreprocessor.remove_cell_tags = ("remove_cell",)
c.TagRemovePreprocessor.remove_all_outputs_tags = ("remove_output",)
c.TagRemovePreprocessor.remove_input_tags = ("remove_input",)
c.TagRemovePreprocessor.enabled = True

# Configure and run out exporter
c.HTMLExporter.preprocessors = ["nbconvert.preprocessors.TagRemovePreprocessor"]

exporter = HTMLExporter(config=c)
exporter.register_preprocessor(TagRemovePreprocessor(config=c), True)

# Configure and run our exporter - returns a tuple - first element with html,
# second with notebook metadata
output = HTMLExporter(config=c).from_filename("your-notebook-file-path.ipynb")

# Write to output html file
with open("your-output-file-name.html", "w") as f:
    f.write(output[0])

This additional example demonstrates using the CLI to remove cells with a certain cell tag

jupyter nbconvert mynotebook.ipynb --TagRemovePreprocessor.enabled=True --TagRemovePreprocessor.remove_cell_tags remove_cell

Removing cells using Regular Expressions on cell content

Sometimes you’d rather remove cells based on their _content_ rather than their tags. In this case, you can use the RegexRemovePreprocessor.

You initialize this preprocessor with a single patterns configuration, which is a list of strings. For each cell, this preprocessor checks whether the cell contents match any of the strings provided in patterns. If the contents match any of the patterns, the cell is removed from the notebook.

For example, execute the following command to convert a notebook to html and remove cells containing only whitespace:

jupyter nbconvert --RegexRemovePreprocessor.patterns="['\s*\Z']" mynotebook.ipynb

The command line argument sets the list of patterns to '\s*\Z' which matches an arbitrary number of whitespace characters followed by the end of the string.

See https://regex101.com/ for an interactive guide to regular expressions (make sure to select the python flavor). See https://docs.python.org/library/re.html for the official regular expression documentation in python.