try... except with unknown error types

Nobody nobody at nowhere.com
Sat Sep 10 11:33:03 CEST 2011


On Wed, 31 Aug 2011 21:01:34 +0000, Chris Torek wrote:

> Still, it sure would be nice to have a static analysis
> tool that could answer questions about potential exceptions. :-) )

That's an impossibility in a dynamic language.

If you call f.read() where f was passed in as a parameter, the exceptions
which f.read() may throw depend upon exactly what f is; there's no
guarantee that it will actually be a built-in file object, only that it
will have a .read() method (otherwise you will get an AttributeError).

Even if f was returned from open(), there's no guarantee that
__builtins__.open() won't have been replaced by the time of the call.




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