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| -rw-r--r-- | pypy/doc/cpython_differences.rst | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/pypy/doc/cpython_differences.rst b/pypy/doc/cpython_differences.rst index 4d2dad06be..984afc89a7 100644 --- a/pypy/doc/cpython_differences.rst +++ b/pypy/doc/cpython_differences.rst @@ -365,14 +365,17 @@ Miscellaneous implementation detail that shows up because of internal C-level slots that PyPy does not have. -* on CPython, ``[].__add__`` is a ``method-wrapper``, and - ``list.__add__`` is a ``slot wrapper``. On PyPy these are normal - bound or unbound method objects. This can occasionally confuse some +* on CPython, ``[].__add__`` is a ``method-wrapper``, ``list.__add__`` + is a ``slot wrapper`` and ``list.extend`` is a (built-in) ``method`` + object. On PyPy these are all normal method or function objects (or + unbound method objects on PyPy2). This can occasionally confuse some tools that inspect built-in types. For example, the standard library ``inspect`` module has a function ``ismethod()`` that returns True on unbound method objects but False on method-wrappers or slot - wrappers. On PyPy we can't tell the difference, so - ``ismethod([].__add__) == ismethod(list.__add__) == True``. + wrappers. On PyPy we can't tell the difference. So on PyPy2 we + have ``ismethod([].__add__) == ismethod(list.extend) == True``; + on PyPy3 we have ``isfunction(list.extend) == True``. On CPython + all of these are False. * in CPython, the built-in types have attributes that can be implemented in various ways. Depending on the way, if you try to |