markerlib 0.4

A compiler for PEP 345 environment markers.

markerlib

Compile or interpret PEP 345 environment markers.

Usage:

>>> import markerlib
>>> marker = markerlib.compile("os.name == 'posix'")
>>> marker(environment=markerlib.default_environment(),
           override={'os.name':'posix'})
True
>>> marker(environment=markerlib.default_environment(),
           override={'os.name':'nt'})
False

The implementation uses the ast to compile environment markers as Python statements with a limited set of allowed node types.

0.4

• Cache compiled marker functions with weakref.WeakValueDictionary

• Rename markerlib.as_function to markerlib.compile

0.3

• Might work on Python 2.5 (includes needed parts of the ast module from Python 2.6+)

• Include 100% test coverage, tox config file

0.1

• Initial version