All 15 functools & Functional Programming Tools questions
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What is the functools module used for in Python? What is the difference between functools.cache and functools.lru_cache? How do you use functools.partial to fix keyword arguments for logging or callback functions? What does functools.reduce do, and why is it often discouraged in favor of loops? How does @functools.wraps preserve metadata when writing decorators? How does functools.total_ordering reduce boilerplate for comparison methods? What does functools.reduce's initializer argument do, and why should you usually provide one? What is the practical difference between using functools.reduce and a plain for-loop for accumulation? How does functools.singledispatch enable function overloading based on argument type? What is functools.cached_property and how does it differ from @property combined with manual caching?
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How does functools.partial work and when is it useful?

Intermediate

Answer

partial creates a new callable with some positional or keyword arguments pre-filled, returning a function with a smaller remaining signature. It's useful for adapting a general function to a specific callback interface, like event handlers or map() calls, without writing a wrapper function or lambda.
from functools import partial

def power(base, exp):
    return base ** exp

square = partial(power, exp=2)
print(square(5))  # 25
Real-world example A GUI framework binds partial(handle_click, button_id=3) as a callback so the click handler already knows which button fired.

Common follow-ups: How is partial different from a lambda?;Can you partial a method?

Decorators;Functions & Scope
All 15 functools & Functional Programming Tools questions