Partial Functions in Python

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

Example:

from functools import partial

# A normal function
def f(a, b, c, x):
    return 1000*a + 100*b + 10*c + x

# A partial function that calls f with
# a as 3, b as 1 and c as 4.
g = partial(f, 3, 1, 4)

# Calling g()
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.

Another Example :

from functools import *

# A normal function
def add(a, b, c):
    return 100 * a + 10 * b + c

# A partial function with b = 1 and c = 2
add_part = partial(add, c = 2, b = 1)

# Calling partial function
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.
• This feature is similar to bind in C++.

This article is contributed by Mayank Rawat .If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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