fnil's cousin from python land

fnone.py

from itertools import izip_longest


def fnone(f, *xs):
    """Takes a function f, and returns a function that calls f, replacing
    a None first argument to f with the supplied value x. Higher arity
    versions can replace arguments in the second and third
    positions (y, z). Note that the function f can take any number of
    arguments, not just the one(s) being None-patched. 
    """
    def g(*args):
        ys = [a if a is not None else b
              for a, b in izip_longest(args, xs)]
        print(ys)
        return f(*ys)
    return g