ProjectMeniscus/meniscus — pull request #126 by dmend (2013-04-04 22:45:32+00:00)
Title: Don't use mutable types for default parameters

Using mutable types for default parameters can lead to buggy code.

Don't do this:
def foo(x=dict()):
pass

Do this:
def foo(x=None):
if x is None:
x = dict()
pass

For more info see Default Parameters: http://docs.python.org/2/reference/compound_stmts.html#function-definitions