How to apply a function to a list in python ?

Created August 30, 2022 | Viewed 341 | by Benjamin Edit


Example of how to apply a function to a list in python:

Apply a function to a list in python using map()

Let's create a list of angles in degrees

mylist = [0,25,45,75,90]

and a function that calculate cos(angle):

import math

def myfunction(angle):
    angle_in_radian = math.radians(angle)
    return math.cos(angle_in_radian)

To apply the function for each items in the list, a solution is to use the python built-in function map() :

list( map(myfunction, mylist) )

gives here

[1.0, 0.9063077870366499, 0.7071067811865476, 0.25881904510252074, 6.123233995736766e-17]

Apply a function to a list in python using numpy

Another possible solution is to convert the list into an array:

import numpy as np

mylist = [0,25,45,75,90]

A = np.array(mylist)

def myfunction(angle):
    angle_in_radian = np.radians(angle)
    return np.cos(angle_in_radian)

print( list( myfunction(A) ) )

gives

[1.0, 0.9063077870366499, 0.7071067811865476, 0.25881904510252074, 6.123233995736766e-17]

References