[Python-Dev] Let's stop eating exceptions in dict lookup (original) (raw)

Armin Rigo arigo at tunes.org
Tue May 30 00:35:57 CEST 2006

Hi Fredrik,

On Tue, May 30, 2006 at 12:23:04AM +0200, Fredrik Lundh wrote:

well, the empty string is a valid substring of all possible strings (there are no "null" strings in Python). you get the same behaviour from slicing, the "in" operator, "replace" (this was discussed on the list last week), "count", etc.

if you're actually searching for a non-empty string, find() will always return -1 sooner or later.

I know this. These corner cases are debatable and different answers could be seen as correct, as I think is the case for find(). My point was different: I was worrying that the recent change in str.find() would needlessly send existing and working programs into infinite loops, which can be a particularly bad kind of failure for some applications.

At least, it gave a 100% performance loss on the benchmark I was trying to run :-)

A bientot,

Armin.

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