Forward compatibility for Python packages, allowing future constructs to be borrowed before they are available in the standard library.
Import functions from the appropriate compat.pyXX module in your python code. When a package is eventually ready to upgrade beyond pyXX, easily locate (with a grep) and replace those functions with the canonical implementations.
Say you want a namedtuple (introduced in Python 2.6) in a project which supports Python 2.5 and greater:
from compat.py25 import namedtuple
MyTuple = namedtuple('MyTuple', 'a b c')
mt = MyTuple(1,2,3)
With jaraco.compat installed, this code will run on Python 2.5 and greater. When the project is ready to move to Python 2.6, one can easily grep for py25 and make the necessary replacements with minimal impact on the code. In this case:
from collections import namedtuple
MyTuple = namedtuple('MyTuple', 'a b c')
mt = MyTuple(1,2,3)