Decorators

gistfile1.py

from functools import  update_wrapper

def decorator(d):
    return lambda fn: update_wrapper(d(fn), fn)

decorator = decorator(decorator)

@decorator
def n_ary(f):
    """Given binary function f(x, y), return an n_ary function such
    that f(x, y, z) = f(x, f(y,z)), etc. Also allow f(x) = x."""
    def n_ary_f(x, *args):
        return x if not args else f(x, n_ary_f(*args))
    return n_ary_f

@n_ary
def add(x,y):
    return x + y

print add(2, 3, 4, 5, 6)