Least common multiple for 3 or more numbers

In Python (modified primes.py):

def gcd(a, b):
    """Return greatest common divisor using Euclid's Algorithm."""
    while b:      
        a, b = b, a % b
    return a

def lcm(a, b):
    """Return lowest common multiple."""
    return a * b // gcd(a, b)

def lcmm(*args):
    """Return lcm of args."""   
    return reduce(lcm, args)

Usage:

>>> lcmm(100, 23, 98)
112700
>>> lcmm(*range(1, 20))
232792560

reduce() works something like that:

>>> f = lambda a,b: "f(%s,%s)" % (a,b)
>>> print reduce(f, "abcd")
f(f(f(a,b),c),d)

You can compute the LCM of more than two numbers by iteratively computing the LCM of two numbers, i.e.

lcm(a,b,c) = lcm(a,lcm(b,c))