diff options
Diffstat (limited to 'numpy/doc/subclassing.py')
| -rw-r--r-- | numpy/doc/subclassing.py | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/numpy/doc/subclassing.py b/numpy/doc/subclassing.py index c42d5e330..7877432b5 100644 --- a/numpy/doc/subclassing.py +++ b/numpy/doc/subclassing.py @@ -431,20 +431,21 @@ The signature of ``__array_ufunc__`` is:: def __array_ufunc__(ufunc, method, *inputs, **kwargs): - - *ufunc* is the ufunc object that was called. - - *method* is a string indicating which Ufunc method was called - (one of ``"__call__"``, ``"reduce"``, ``"reduceat"``, - ``"accumulate"``, ``"outer"``, ``"inner"``). - - *inputs* is a tuple of the input arguments to the ``ufunc``. - - *kwargs* is a dictionary containing the optional input arguments - of the ufunc. If given, any ``out`` arguments, both positional - and keyword, are passed as a :obj:`tuple` in *kwargs*. + - *ufunc* is the ufunc object that was called. + - *method* is a string indicating how the Ufunc was called, either + ``"__call__"`` to indicate it was called directly, or one of its + :ref:`methods<ufuncs.methods>`: ``"reduce"``, ``"accumulate"``, + ``"reduceat"``, ``"outer"``, or ``"at"``. + - *inputs* is a tuple of the input arguments to the ``ufunc`` + - *kwargs* contains any optional or keyword arguments passed to the + function. This includes any ``out`` arguments, which are always + contained in a tuple. A typical implementation would convert any inputs or ouputs that are instances of one's own class, pass everything on to a superclass using ``super()``, and finally return the results after possible back-conversion. An example, taken from the test case -``test_ufunc_override_with_super`` in ``core/tests/test_umath.pu``, is the +``test_ufunc_override_with_super`` in ``core/tests/test_umath.py``, is the following. .. testcode:: @@ -462,9 +463,9 @@ following. else: args.append(input_) - outputs = kwargs.pop('out', []) + outputs = kwargs.pop('out', None) out_no = [] - if outputs: + if outputs is not None: out_args = [] for j, output in enumerate(outputs): if isinstance(output, A): @@ -474,9 +475,11 @@ following. out_args.append(output) kwargs['out'] = tuple(out_args) - info = {key: no for (key, no) in (('inputs', in_no), - ('outputs', out_no)) - if no != []} + info = {} + if in_no: + info['inputs'] = in_no + if out_no: + info['outputs'] = out_no results = super(A, self).__array_ufunc__(ufunc, method, *args, **kwargs) @@ -488,7 +491,7 @@ following. return results results = (results,) - if outputs == []: + if outputs is None: outputs = [None] * len(results) results = tuple(result.view(A) if output is None else output for result, output in zip(results, outputs)) |