Version 15 (modified by xi, 11 years ago) (diff)



PyYAML is a YAML parser and emitter for Python.


 YAML is a data serialization format designed for human readability and interaction with scripting languages.

PyYAML is a YAML parser and emitter for the Python programming language.

PyYAML features

  • a complete  YAML 1.1 parser. In particular, PyYAML can parse all examples from the specification. The parsing algorithm is simple enough to be a reference for YAML parser implementors.
  • Unicode support including UTF-8/UTF-16 input/output and \u escape sequences.
  • low-level event-based parser and emitter API (like SAX).
  • high-level API for serializing and deserializing native Python objects (like DOM or pickle).
  • support for all types from the  YAML types repository. A simple extension API is provided.
  • relatively sensible error messages.

Note that PyYAML is still young and may have some bugs. Furthermore, PyYAML is written in Python and is slow comparing to C based parsers.


PyYAML requires Python 2.3 or higher.

Download and Installation

The current stable release of PyYAML: 3.03.

Download links:

Unpack the archive and install the package by executing

$ python install

You may check out the latest development code of PyYAML from the Subversion repository

$ svn checkout pyyaml-trunk


Quick example:

>>> import yaml

>>> print yaml.load("""
... name: Vorlin Laruknuzum
... sex: Male
... class: Priest
... title: Acolyte
... hp: [32, 71]
... sp: [1, 13]
... gold: 423
... inventory:
... - a Holy Book of Prayers (Words of Wisdom)
... - an Azure Potion of Cure Light Wounds
... - a Siver Wand of Wonder
... """)

{'name': 'Vorlin Laruknuzum', 'gold': 423, 'title': 'Acolyte', 'hp': [32, 71],
'sp': [1, 13], 'sex': 'Male', 'inventory': ['a Holy Book of Prayers (Words of Wisdom)',
'an Azure Potion of Cure Light Wounds', 'a Siver Wand of Wonder'], 'class': 'Priest'}

>>> print yaml.dump({'name': "The Cloak 'Colluin'", 'depth': 5, 'rarity': 45,
... 'weight': 10, 'cost': 50000, 'flags': ['INT', 'WIS', 'SPEED', 'STEALTH']})

name: The Cloak 'Colluin'
rarity: 45
weight: 10
cost: 50000
depth: 5

For more details, please check PyYAML Documentation.


3.03 (2006-06-19)

  • Fix Python 2.5 compatibility issues.
  • Fix numerous bugs in the float handling.
  • Fix scanning some ill-formed documents.
  • Other minor fixes.

3.02 (2006-05-15)

  • Fix win32 installer. Apparently bdist_wininst does not work well under Linux.
  • Fix a bug in add_path_resolver.
  • Add the yaml-highlight example. Try to run on a color terminal: python <any_document.yaml.

3.01 (2006-05-07)

  • Initial release. The version number reflects the codename of the project (PyYAML 3000) and differenciates it from the abandoned PyYaml module.

Development and bug reports

You may check out the PyYAML source code from  PyYAML SVN repository.

If you find a bug in PyYAML, please file a bug report. You may review open bugs through the list of open tickets.

You may discuss PyYAML at  the YAML-core mailing list.

Author and copyright

The PyYAML module is written by Kirill Simonov.

PyYAML is released under the MIT license.