canonical file access pattern?

Hans-Joachim Widmaier hjwidmaier at
Wed Dec 31 18:28:49 CET 2003

Am Wed, 31 Dec 2003 14:51:01 +0000 schrieb John J. Lee:

> If that were true, why did exceptions get invented?  If you don't need
> to do something different in all those except: clauses, then don't put
> them in. 

One thing I need is to create an informative and useful error message

> As you know, the nice thing about exceptions is that you're
> allowed to handle them in sensible places, so typical usage is like
> this:

[handling exceptions in the caller]

> Shock, horror, where's the except IOError:, you ask?!  It's in the
> calling function, of course.

Hmm. The farther away from the actual point of error you catch it, the
harder it is to tell exactly what happened and to redo/work around it.

> Also, if you want to catch both OSError and IOError, note that
> EnvironmentError is their common base class.

Good tip! I didn't know that before.

Hans-Joachim Widmaier

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