Conway's Game of Life in Python

CGoL.py

from random import randint
from os import system
from time import sleep
from copy import deepcopy

xs, ys = 210, 100
c  = [[randint(0,1) for _ in range(ys)] for _ in range(xs)]
cn = [[0 for _ in range(ys)] for _ in range(xs)]

while True:
    system('clear')
    for j in range(ys):
        print(''.join(['*' if c[i][j] else ' ' for i in range(xs)]))
    for j in range(ys):
        for i in range(xs):
            t = 0
            for k in [-1,0,1]:
                for l in [-1,0,1]:
                    t += 0 if k==0 and l==0 else c[(i+l)%xs][(j+k)%ys]
            if c[i][j]: cn[i][j] = 1 if t==2 or t==3 else 0
            else:       cn[i][j] = 1 if t==3 else 0
    c = deepcopy(cn)
    sleep(0.1)