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.