[Python-Dev] other "magic strings" issues
Guido van Rossum
guido at python.org
Fri Nov 7 17:49:31 EST 2003
> I guess the tests should be faster, yes, but I would still want _iterables_
> for ascii_* and digits.
Why? It's not like you're going to save much space by not creating a
string of 52 bytes.
> One issue with allowing "if char in string.letters:" is that these
> days this will not raise if the alleged 'char' is more than one
> character -- it will give True for (e.g.) 'ab', False for (e.g.)
> 'foobar', since it tests _substrings_.
> So, maybe, str.letters and friends should be iterables which also
> implement a __contains__ method that raises some error with helpful
> information about using .iswhatever() instead -- that's assuming we
> want people NOT to test with "if char in str.letters:". If we DO
> want people to test that way, then I think str.letters should
> _still_ have __contains__, but specifically one to optimize speed in
> this case (if supported it should be just as fast as the
> .is... method -- which as Skip reminds us may in turn need
Hm. The iterable idea seems overblown for something as simple as
--Guido van Rossum (home page: http://www.python.org/~guido/)
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