[Python-Dev] avoiding accidental shadowing of top-level libraries by the main module (original) (raw)

Nick Coghlan ncoghlan at gmail.com
Tue Jul 13 23:02:40 CEST 2010

On Wed, Jul 14, 2010 at 2:25 AM, Michael Foord <fuzzyman at voidspace.org.uk> wrote:

Sure - there are trivial workarounds which is why I don't think there are many genuine use cases for a module reimporting itself with a different name.

My concerns aren't about a module reimporting itself directly, they're about the case where a utility module is invoked as main but is also imported normally somewhere else in a program (e.g. pdb is invoked as a top-level debugger, but is also imported directly for some reason). Currently that works as a non-circular import and will only cause hassles if there is top-level state in the affected module that absolutely must be a singleton within a given application. Either change (disallowing it completely as you suggest, or making it a circular import, as I suggest) runs the risk of breaking code that currently appears to work correctly.

Fred's point about the practice of changing name in the main module corrupting generated pickles is one I hadn't thought of before though.

Cheers, Nick.

-- Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia

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