funcie

funcie is a focused Python library of functional programming helpers.

What you get

• Function composition: compose, pipe, composable
• Predicate composition: predicate with &, |, ^, ~
• Predicate helpers: all_pass, any_pass, none_pass, complement
• Currying: curry, curry_n, curried
• Collection helpers: keep, reject, flat_map, take, drop, partition, fold

Install

uv sync --group dev

Quick examples

Composition

from funcie import compose, pipe, composable

add1 = lambda x: x + 1
mul2 = lambda x: x * 2

assert compose(add1, mul2)(3) == 7
assert pipe(add1, mul2)(3) == 8

c_add1 = composable(add1)
c_mul2 = composable(mul2)
assert (c_add1 >> c_mul2)(3) == 8
assert (c_add1 @ c_mul2)(3) == (4, 6)

Predicates

from funcie import predicate

is_even = predicate(lambda n: n % 2 == 0)
is_positive = predicate(lambda n: n > 0)

is_positive_even = is_even & is_positive
is_odd = ~is_even

assert is_positive_even(4) is True
assert is_positive_even(-2) is False
assert is_odd(5) is True

Currying

from funcie import curried

@curried
def add(a, b, c):
    return a + b + c

assert add(1)(2)(3) == 6

Development

make ci