ok so this probably isn't what I should be doing, but it definitely isn't what python should be doing

gistfile1.py

>>> def foo(bar=None):
...     def baz():
...             if not bar: bar = 'goo'
...             print bar
...     baz()
... 
>>> foo()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 5, in foo
  File "<stdin>", line 3, in baz
UnboundLocalError: local variable 'bar' referenced before assignment