Steven D'Aprano <steve at REMOVE-THIS-cybersource.com.au> writes: > You can't just say: > product = map(operator.mul, [A*T*C*G]*200000) > and expect to get anywhere. from math import log A,T,C,G = (0.35, 0.30, 0.25, 0.10) c,m = divmod(200000*log(A*T*C*G,10), 1) print "%.3fe%d"%(m, int(c))