On 6 Mar, 19:46, Gary Herron <gher...@islandtraining.com> wrote: > It is an implementation choice (usually driven by efficiency considerations) > to choose when two strings with the same value are stored in memory once or > twice. In order for Python to recognize when a newly created string has the > same value as an already existing string, and so use the already existing > value, it would need to search *every* existing string whenever a new string > is created. Clearly that's not going to be efficient. However, the C > implementation of Python does a limited version of such a thing -- at least > with strings of length 1.
Gary, thanks for your reply: your explanation does pretty much answer my question. One thing I can add however is that it really seems that non-alphanumeric characters such as the forward slash make the difference, not just the number of characters. I.e. >>> a = "aaaaaaaaaaaaaaaaaaaaaaaaaaa" >>> b = "aaaaaaaaaaaaaaaaaaaaaaaaaaa" >>> a is b True >>> a = "/aaaaaaaaaaaaaaaaaaaaaaaaaaa" >>> b = "/aaaaaaaaaaaaaaaaaaaaaaaaaaa" >>> a is b False I just find it peculiar more than a nuisance, but I'll go to the blackboard and write 100 times "never compare the identities of two immutables". Thank you all! Manu -- http://mail.python.org/mailman/listinfo/python-list
