Hi! I would like to report what I think is a possible bug (in cython or corresponding documentation).
According to: <http://docs.cython.org/src/userguide/extension_types.html#extension-types-and-none> [...] The self parameter of a method of an extension type is guaranteed never to be None. [...] However given this snippet: [...] cdef class test: def __sub__(self, test rhs not None): print "self is %s" % repr(self), "rhs is %s" % repr(rhs) [...] If I then load it python: In [1]: import test In [2]: x = test.test() In [3]: None - x self is None rhs is <test.test object at 0x7fdd9eeb7410> Thus showing that in this case "self" was actually initialized with None. If I explictly add "not None" as in: [...] cdef class test: def __sub__(self not None, test rhs not None): print "self is %s" % repr(self), "rhs is %s" % repr(rhs) [...] In [3]: None - x TypeError: Argument 'self' must not be None [...] Which is good. If I instead add "test self" as in: [...] cdef class test: def __sub__(test self not None, test rhs not None): print "self is %s" % repr(self), "rhs is %s" % repr(rhs) [...] In [3]: None - x TypeError: Argument 'self' has incorrect type (expected test.test, got NoneType) [...] What's worse is that if I use "test self" (without not None), the same TypeError is not raised: [...] cdef class test: def __sub__(test self, test rhs not None): print "self is %s" % repr(self), "rhs is %s" % repr(rhs) [...] In [3]: None - x self is None rhs is <test.test object at 0x7f17b36ff3f0> Thus we have: self -> not respecting None-checking (in disagreement with Documentation) self not None -> OK test self -> not respecting type-checking! test self non None -> OK (respecting type-checking, hence None-checking). Hope that helps. Cheers, Samuele -- Samuele Kaplun Invenio Developer ** <http://invenio-software.org/> _______________________________________________ cython-devel mailing list cython-devel@python.org https://mail.python.org/mailman/listinfo/cython-devel
