gistfile1.py

mydict = {}
mydict['penis'] = "boner"

def thing_one():
     for k,v in mydict.items():
             print "%s %s" % (k,v)

def thing_two():
     for k,v in mydict.items():
             print "%s %s" % (k,v)
     mydict = {}
     

>>> thing_one()
penis boner
>>> thing_two()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in thing_two
UnboundLocalError: local variable 'mydict' referenced before assignment