Composable functions

composable.py

from functools import wraps


def composable(f1):
    @wraps(f1)
    def wrapper(*args, **kwargs):
        if not kwargs and len(args) == 1 and callable(args[0]):
            f2 = args[0]

            @wraps(f2)
            def composed(*a, **k):
                return f1(f2(*a, **k))

            return composable(composed)
        else:
            return f1(*args, **kwargs)

    return wrapper