Partial Functions in Python

Introduction

Partial functions allow us to fix a certain number of arguments of a function and generate a new function.

from functools import partial

def f(a, b, c, x):

    return 1000*a + 100*b + 10*c + x

g = partial(f, 3, 1, 4)

print(g(5))

OUTPUT :

3145

In the example we have pre-filled our function with some constant values of a, b and c. And g() just takes a single argument i.e. the variable x.

from functools import *

def add(a, b, c):

    return 100 * a + 10 * b + c

add_part = partial(add, c = 2, b = 1)

print(add_part(3))

OUTPUT :

312

Partial functions can be used to derive specialized functions from general functions and therefore help us to reuse our code.