Dynamic method creation does not work as excpected

gistfile1.py

>>> class API:
...     def __init__(self):
...         pass
... 
>>> for i in range(10):
...     name = "print_number_%i" % i
...     def print_func(self):
...         print "my result is", i
...     setattr(API, name, print_func)
... 
>>> api = API()
>>> api.print_number_3()
my result is 9
>>> # why not 3?!
>>>