functools.partial

Create a new function with some of the arguments set in advance.

Python 3.13
functools.partial(func, /, *args, **keywords)

Parameters

funcCallable: The original function.
*argsAny: Positional arguments that go first.
**keywordsAny: Keyword arguments; they can be overridden in a call.

Return value

A partial object that is called like a regular function.

Examples

A function with a ready greeting

Python 3.13
from functools import partial


def greet(greeting, name):
    return f'{greeting}, {name}!'


hello = partial(greet, 'Hello')
print(hello('Anna'))
Hello, Anna!

int with base 2

Python 3.13
from functools import partial

from_binary = partial(int, base=2)
print(from_binary('1010'))
10

Details

Arguments passed in a call are added after the preset ones. Keyword values can be replaced in a call: from_binary("12", base=10) gives 12. The original function and arguments are stored in the func, args and keywords attributes.