New submission from INADA Naoki: http://docs.python.org/3.3/glossary.html#term-sequence
__getitem__ and __len__ are required for sequence type. (__iter__ is not required because types having __getitem__ are already iterator.) .__contains__(), .index() and .count() is not required for sequence. For example, following class should be sequence. class Foo: def __getitem__(self, index): if not isinstance(index, int): raise TypeError if index >= 3: raise IndexError return index def __len__(self): return 3 ---------- components: Library (Lib) messages: 177737 nosy: naoki priority: normal severity: normal status: open title: collections.abc.Sequence shoud provide __subclasshook__ versions: Python 3.3, Python 3.4, Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue16728> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com