lambda-talks.py

def multiply(a, b):
    # Assuming a and b are not negative
    if b == 0: return 0
    if b == 1: return a
    return a + multiply(a, b-1)

def power(b, e):
    # Assuming e is not negative
    if e == 0: return 1
    if e == 1: return b
    return multiply(b, power(b, e-1))

def random_test (func, builtin_func):
    import random, sys, resource
    # increment the stack depth
    sys.setrecursionlimit(1000000)
    # ulimit tweak
    resource.setrlimit(resource.RLIMIT_STACK, (resource.RLIM_INFINITY, resource.RLIM_INFINITY))

    for a in range (0, 7):
        b = random.randint(0, 7)
        assert func(a, b) == builtin_func(a, b)

import operator
random_test(multiply, operator.mul)
random_test(power, operator.pow)