ctypのインポートでImportErrorが発生するのはなぜですか？

Question

Python 2.6.2 (r262:71605, Apr 14 2009, 22:40:02) [MSC v.1500 32 bit (Intel)] on 
win32 
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>>> import ctypes 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
    File "C:\Python26\lib\ctypes\__init__.py", line 17, in <module> 
    from struct import calcsize as _calcsize 
ImportError: cannot import name calcsize 

>>> from ctypes import * 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
    File "C:\Python26\lib\ctypes\__init__.py", line 17, in <module> 
    from struct import calcsize as _calcsize 
ImportError: cannot import name calcsize 
>>> 

Answer 1

パスのどこかに別のstruct.pyがあるようです。

>>> import inspect 
>>> import struct 
>>> inspect.getabsfile(struct) 
'c:\\python26\\lib\\struct.py'