cmarkgfm - Python bindings to GitHub's cmark

Minimalist Python bindings to GitHub's fork of cmark.

Installation

This package is published on PyPI as cmarkgfm <https://pypi.org/project/cmarkgfm/>__ and can be installed with pip or pipenv::

pip install --user cmarkgfm
pipenv install cmarkgfm

Wheels are provided for macOS, Linux, and Windows for Python 3.6, 3.7, 3.8, 3.9, 3.10 and 3.11.

Usage

High-level usage is really straightforward. To render normal CommonMark markdown:

.. code-block:: python

import cmarkgfm

html = cmarkgfm.markdown_to_html(markdown_text)

To render GitHub-flavored markdown:

.. code-block:: python

import cmarkgfm

html = cmarkgfm.github_flavored_markdown_to_html(markdown_text)

Advanced Usage

Options

Both rendering methods markdown_to_html and github_flavored_markdown_to_html have an optional options argument that can be used to activate options of cmark <https://manpages.debian.org/stretch/cmark/cmark.1.en.html>_. For example:

.. code-block:: python

import cmarkgfm
from cmarkgfm.cmark import Options as cmarkgfmOptions

options = (
    cmarkgfmOptions.CMARK_OPT_GITHUB_PRE_LANG
    | cmarkgfmOptions.CMARK_OPT_SMART
)
html = cmarkgfm.markdown_to_html(markdown_text, options)

The options are:

+-----------------------------------------+----------------------------------------------------+ | Option | Effect | +=========================================+====================================================+ | CMARK_OPT_UNSAFE (>=0.5.0) | Allows rendering unsafe HTML and links. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_SAFE (<0.5.0) | Prevents rendering unsafe HTML and links. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_SMART | Render curly quotes, en/em-dashes, ellipses | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_NORMALIZE | Consolidate adjacent text nodes. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_HARDBREAKS | Renders line breaks within paragraphs as <br> | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_NOBREAKS | Render soft line breaks as spaces. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_SOURCEPOS | Adds data-sourcepos to HTML tags indicating | | | the corresponding line/col ranges in the input | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_FOOTNOTES | Parse footnotes. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_VALIDATE_UTF8 | Validate UTF-8 in the input before parsing, | | | replacing illegal sequenceswith the replacement | | | character U+FFFD. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_GITHUB_PRE_LANG | Use GitHub-style tags for code blocks. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_LIBERAL_HTML_TAG | Be liberal in interpreting inline HTML tags. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_STRIKETHROUGH_DOUBLE_TILDE | Only parse strikethroughs if surrounded by exactly | | | 2 tildes. Gives some compatibility with redcarpet. | +-----------------------------------------+----------------------------------------------------+ | CMARK_OPT_TABLE_PREFER_STYLE_ATTRIBUTES | Use style attributes to align table cells instead | | | of align attributes. | +-----------------------------------------+----------------------------------------------------+

Unsafe rendering

Since version 0.5.0, the default behavior is safe. In earlier versions, the default behavior is unsafe, as described below. To render potentially unsafe HTML since 0.5.0 pass the CMARK_OPT_UNSAFE option.

CommonMark can render potentially unsafe HTML, including raw HTML, raw Javascript, and potentially unsafe links (including links that run scripts). Although github_flavored_markdown_to_html prevents some raw HTML tags (including script) from being rendered, it does not block unsafe URLs in links.

Therefore it is recommend to call the rendering method with the SAFE option turned on. The safe option does not render raw HTML or potentially dangerous URLs. (Raw HTML is replaced by a placeholder comment; potentially dangerous URLs are replaced by empty strings.) Dangerous URLs are those that begin with javascript:, vbscript:, file:, or data: (except for image/png, image/gif, image/jpeg, or image/webp mime types) To do this, use:

.. code-block:: python

# cmarkgfm<0.5.0
import cmarkgfm
from cmarkgfm.cmark import Options as cmarkgfmOptions

html = cmarkgfm.markdown_to_html(markdown_text, options=cmarkgfmOptions.CMARK_OPT_SAFE)
# or
html = cmarkgfm.github_flavored_markdown_to_html(markdown_text, options=cmarkgfmOptions.CMARK_OPT_SAFE)

If you trust the markdown text to not include any unsafe tags and links, then you may skip this.

Contributing

Pull requests are welcome. :)

License

This project is under the MIT License. It includes components under differing copyright under the third_party directory in this source tree.