Franklin? Lee added the comment: > Although I still think it's telling readers incorrect info in the second > part. For ``bool``, it is not equivalent to ``(item for item in iterable if > function(item))`` but ``(item for item in iterable if item)``. For CPython, > you are not telling the truth.
What do you mean by, "it is not equivalent"? Are you saying that the first one will give a different result from the second? In general, when interpreting an object in a boolean context, Python will do the "equivalent" of calling ``bool`` on it, where "equivalent" in the docs means "has the same result as". See, for example, the ``itertools`` docs: https://docs.python.org/3/library/itertools.html#itertools.accumulate -------- In this case: If ``filter`` is passed ``None`` or ``bool``, it will call "PyObject_IsTrue" on the object. (https://github.com/python/cpython/blob/c750281ef5d8fa89d13990792163605302e972d4/Python/bltinmodule.c#L481) "PyObject_IsTrue" is defined here: https://github.com/python/cpython/blob/6aea3c26a22c5d7e3ffa3d725d8d75dac0e1b83b/Objects/object.c#L1223 On the other hand, ``bool`` is defined here, as "PyBool_Type": https://github.com/python/cpython/blob/c750281ef5d8fa89d13990792163605302e972d4/Python/bltinmodule.c#L2686 "PyBool_Type" is defined here, with the ``bool.__new__`` function defined as "bool_new": https://github.com/python/cpython/blob/2d264235f6e066611b412f7c2e1603866e0f7f1b/Objects/boolobject.c#L133 "bool_new" is defined here, using "PyObject_IsTrue": https://github.com/python/cpython/blob/2d264235f6e066611b412f7c2e1603866e0f7f1b/Objects/boolobject.c#L43 Both "filter_next" and "bool_new" call "PyObject_IsTrue" and take 0 as False, positive as True, and negative as an error. So it's equivalent to calling ``bool``, but the "bool_new" call is sort of inlined. Does that clear things up? ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue27000> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
