numpy.frompyfunc

numpy.frompyfunc(func, /, nin, nout, *[, identity])

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:

funcPython function object

An arbitrary Python function.

ninint

The number of input arguments.

noutint

The number of objects returned by func.

identityobject, optional

The value to use for the identity attribute of the resulting object. If specified, this is equivalent to setting the underlying C identity field to PyUFunc_IdentityValue. If omitted, the identity is set to PyUFunc_None. Note that this is _not_ equivalent to setting the identity to None, which implies the operation is reorderable.

Returns:

outufunc

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(['0o12', '0o36', '0o144'], dtype=object)
>>> np.array((oct(10), oct(30), oct(100))) # for comparison
array(['0o12', '0o36', '0o144'], dtype='<U5')