[Python-Dev] Dots in __name__ break import -- fixable?

Guido van Rossum guido at python.org
Tue Jan 6 18:18:00 EST 2004

> There must be some code in the import machinery that assumes (with 
> excellent reason) that the __name__ of the module from which it is 
> called will never contain periods.

Right.  Periods in module names are used for the package namespace.
(Import some code that uses packages and then print sys.modules.keys()
to see how.)

> Consider the following:
>  >>> __name__ = 'a.b.c'
>  >>> import string
>  >>> string
> <module 'a.b.string' from '/usr/lib/python2.3/string.pyc'>
> The peculiar behavior is *only* triggered by periods:
>  >>> __name__ = ''.join(map(chr, range(1, 256))).replace('.', '')
>  >>> import string
>  >>> string
> <module 'string' from '/usr/lib/python2.3/string.pyc'>
> Would this be easy to fix?


> It would fall into the realm of "so don't do that!" except that Zope's 
> Python Scripts set their __name__ to their Zope Id, which can contain 
> periods.

Too bad.

--Guido van Rossum (home page: http://www.python.org/~guido/)

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