Version 16 (modified by tim@…, 11 years ago) (diff)



Python bindings for the Syck YAML parser and emitter


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

 Syck is an extension for reading and writing YAML in scripting languages. Syck provides bindings to the  Python programming language, but they are somewhat limited and leak memory.

PySyck is aimed to update the current Python bindings for Syck. The new bindings provide a wrapper for the Syck emitter and give access to YAML representation graphs. Hopefully it will not leak memory as well.

PySyck may be used for various tasks, in particular, as a replacement of the module  pickle.

Projects using PySyck

If your project uses PySyck, feel free to add its URL along with a small note.

 The Official Python Programming Language Website.

 Pyramid is a simple, file based website templating system. Pyramid uses Nevow as its templating system and YAML as the format for its file based data.

 Pollenation Internet use yaml and pysyck in many project sites (e.g. The  Super League, The Oman Ministry of Foreign affairs, London Bridge Hospital). It is primarily used for configuration but some non technical clients also use it for general site data.


PySyck requires Python 2.3 or higher and Syck 0.55 or higher.

You may download the latest Syck release from Alternatively you download my unofficial syck tarball. It is the code from  the Syck SVN repository with my SyckPatches applied.


The latest version

Syck Source

I prepared an unofficial syck tarball:

There are source/binary rpm package(s) in a yum repository compiled against Fedora Core 5 at


Windows binaries

Changes from 0.55.1 to 0.61.1

  • build: check the presence of syck.h and print a helpful message if it is not found.
  • Release GIL when calling syck.
  • Change the way !str-tagged scalars are converted. If a scalar contains only ASCII characters, it is converted to a plain string object. If it is a valid UTF-8 sequence, it is converted to a Unicode object. Otherwise leave it as is, and issue a warning.
  • Windows binaries are built against
  • The new home of PySyck is

Older versions


Windows binaries


Quick example:

>>> from syck import *
>>> print load("""
... - foo
... - bar
... - baz
... """)
['foo', 'bar', 'baz']
>>> print dump(['foo', 'bar', 'baz'])
- foo
- bar
- baz

For more details, please check README.txt.

Development and Bug reports

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

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

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

Author and Copyright

The PySyck module is written by Kirill Simonov.

PySyck is released under the BSD license like Syck itself.