SciPy

numpy.frompyfunc

numpy.frompyfunc(func, nin, nout)

Takes an arbitrary Python function and returns a Numpy ufunc.

Can be used, for example, to add broadcasting to a built-in Python function (see Examples section).

Parameters:

func : Python function object

An arbitrary Python function.

nin : int

The number of input arguments.

nout : int

The number of objects returned by func.

Returns:

out : ufunc

Returns a Numpy universal function (ufunc) object.

See also

vectorize
evaluates pyfunc over input arrays using broadcasting rules of numpy

Notes

The returned ufunc always returns PyObject arrays.

Examples

Use frompyfunc to add broadcasting to the Python function oct:

>>> oct_array = np.frompyfunc(oct, 1, 1)
>>> oct_array(np.array((10, 30, 100)))
array([012, 036, 0144], dtype=object)
>>> np.array((oct(10), oct(30), oct(100))) # for comparison
array(['012', '036', '0144'],
      dtype='|S4')

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