numpy.frompyfunc() in Python
numpy.frompyfunc(func, nin, nout) function allows to create an arbitrary Python function as Numpy ufunc (universal function).
Parameters:
func: [A python function object ] An arbitrary python function
nin: [int] Number of input arguments to that function.
nout: [int] Number of objects returned by that function.
Return: A Numpy universal function object.Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.
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For example, abs_value = numpy.frompyfunc(abs, 1, 1) will create a ufunc that will return the absolute values of array elements.
Code #1:
Python3
# Python code to demonstrate the# use of numpy.frompyfuncimport numpy as np# create an array of numbersa = np.array([34, 67, 89, 15, 33, 27])# python str function as ufuncstring_generator = np.frompyfunc(str, 1, 1)print("Original array-", a)print("After conversion to string-", string_generator(a)) |
Original array- [34 67 89 15 33 27] After conversion to string- ['34' '67' '89' '15' '33' '27']
Code #2:
Python3
# Python code to demonstrate# user-defined function as ufuncimport numpy as np# create an array of numbersa = np.array([345, 122, 454, 232, 334, 56, 66])# user-defined function to check# whether a no. is palindrome or notdef fun(x): s = str(x) return s[::-1]== s # 'check_palindrome' as universal functioncheck_palindrome = np.frompyfunc(fun, 1, 1)print("Original array-", a)print("Checking of number as palindrome-", check_palindrome(a)) |
Original array- [345 122 454 232 334 56 66] Checking of number as palindrome- [False False True True False False True]
Note: This custom ufunc created using frompyfunc always accept a ndarray as an input argument and also return a ndarray object as output.
