null kwargs strangeness

null-kwargs.py

#!/usr/bin/env python

def some_operation(foo=0):
	print ("foo is %r" % foo)

def kwargs_print(**kwargs):
	print ("you gave me %r" % kwargs)


a = {}
kwargs_print(**a)
some_operation(**a)

a = {'foo': 1}
kwargs_print(**a)
some_operation(**a)

a = {'foo\0bar': 2}
kwargs_print(**a)
some_operation(**a)

# on py2.7.2, throws:
#   TypeError: some_operation() got an unexpected keyword argument 'foo'
# on py3.3.0, throws:
#   TypeError: some_operation() got an unexpected keyword argument 'foo bar'