list.index() and list.tuple() don't currently accept None as slice parameters, as reported in http://bugs.python.org/issue13340. For example:
>>> [1, 2, 3].index(2, None, None) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: slice indices must be integers or None or have an __index__ method The error message of list.index() and tuple.index() (as a consequence of using _PyEval_SliceIndex() for parsing arguments) indicates that None is a valid value. Currently, find(), rfind(), index(), rindex(), count(), startswith() and endswith() of str, bytes and bytearray accept None. Should list.index() and tuple.index() accept it, too? I'm bringing this up because I already committed a fix that enables the None arguments, but Raymond pointed out that maybe they shouldn't accept None at all. I also committed the fix to 3.2 and 2.7 based on discussion in http://bugs.python.org/issue11828#msg133532, in which Raymond says that for string functions, this can be considered a bug because the exception's error message makes a promise that None is accepted. Petri _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
