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.

参见

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:

>>> import numpy as np
>>> 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')