Create matrix
Create matrix of None
A = [[ None for _ in xrange(M)] for _ in xrange(N)]
Create matrix of random numbers
import random
A = [[ random.random() for _ in xrange(M)] for _ in xrange(N)]
Generator for lists of M random elements
import random
A = ([ random.random() for _ in xrange(M)] for _ in iter(int, 1))
for i in A:
print i
sleep(0.2)