交替颜色画一排正方形

from turtle import *
from random import *
speed(0)
penup()
goto(-190,0)
pendown()

for j in range(8):
if j%2==0:
color('red')
else:
color('blue')
begin_fill()
for i in range(4):
fd(30)
left(90)
end_fill()
penup()
goto(-190+(j+1)*50, 0)
pendown()

input()