imp#reload

reload.py

$ cat a.py
class A(object):
  def __init__(self):
    pass
$ python
Python 2.7.8 |Anaconda 2.1.0 (64-bit)| (default, Aug 21 2014, 18:22:21)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] on linux2
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>>> from a import A
>>> import imp
>>> imp.reload(a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'a' is not defined
>>> import a
>>> a.A
<class 'a.A'>
>>> imp.reload(a)
<module 'a' from 'a.pyc'>
>>>