The Pygments Pseudocode Lexer

Site Contents:

• Lexers
  • AlgPseudocode and Language Variants
  • FrPseudocode
• Filters
  • TokenReplaceFilter
  • ErrorToGenericErrorTokenFilter
• Changes
  • Version 3 Series
  • Version 2 Series
  • Breaking Changes
• Licenses

• Search Page

Version:

3.0

Date:

2026-05-23

Copyright:

• © 2026 Franz Glasner

• © 2015 Simon Wachter

License:

MIT License

Revision:

cd22c2e8390d

This package contains Pygments lexers for some variants of pseudocode.

Initially a fork of pygments-lexer-pseudocode it has been considerably changed and expanded.

It now contains the following lexers:

Language Name	Description	Extension(s)	Aliases / Short Name(s)	Lexer Class
AlgPseudocode	Pseudocode lexer inspired by CTAN’s Algpseudocodex	*.algpseudocode, *.algpseudo	algpseudocode, algpseudo	AlgPseudocodeLexer
AlgPseudocodeFR	AlgPseudocode with french keyword expansion	*.algpseudo-fr, *.algpseudocode-fr	algpseudocode-fr, algpseudo-fr	AlgPseudocodeLexer_FR
AlgPseudocodeDE	AlgPseudocode with german keyword expansion	*.algpseudo-de, *.algpseudocode-de	algpseudocode-de, algpseudo-de	AlgPseudocodeLexer_DE
FrPseudocode	The original lexer from pygments-lexer-pseudocode – renamed and slightly changed	*.fr-algo, *.fr-pseudocode	fr-pseudocode, fr-pseudo, fr-algorithm, fr-algo	FrPseudocodeLexer

It additionally contains the following filters:

Filter Name	Description	Filter Class
tokenreplace	A configurable token replacer: replace a given token type by another given token type in a stream	TokenReplaceFilter
errortogenericerror	Replace all Error tokens in a stream by Generic.Error tokens	ErrorToGenericErrorTokenFilter

Installation

The lexers and filters are available as a Python wheel package:

pip install pygments-lexer-pseudocode2

Alternatively, to build from the source code repository:

python -m build

Usage

After installation all the Pseudocode lexers and filters automatically register itself with the plugin system of Pygments. Their respective aliases and filename extensions are made known to Pygments.

Usage is easy:

Pygmentizing a file with a known file extension:

pygmentize document.algpseudocode

Or you can manually select the Pseudocode lexer you want to use by using a command line flag:

pygmentize -l algpseudocode somefile

Within Sphinx use a lexer like this:

.. code-block:: algpseudocode

Licenses

The package is licensed under the terms of the MIT Licence.

Some code snippets are licensed under the terms of the BSD 2-Clause “Simplified” License as they are taken from the Python lexer that is included in Pygments.