[Solved] Incorrect pattern displayed

Assuming you want it to print out 6 patterns of 6 stars with a line between, this is what you want to do:

import sys

n = 0
a = 0

while (n < 6):
    n = n + 1
    a=0
    while(a < n):
        sys.stdout.write('*',end="")
        a = a +1
    print ''