>>> def lcm(p,q):
p, q = abs(p), abs(q)
m = p * q
if not m: return 0
while True:
p %= q
if not p: return m // q
q %= p
if not q: return m // p
>>> lcm(-6, 14)
42
>>> lcm(12, 18)
36
>>> lcm(2, 0)
0
>>>