import turtle
import random
t = turtle.Turtle()
t.speed(0) # 1:slowest, 3:slow, 5:normal, 10:fast, 0:fastest

while(True):
  t.forward(50)
  x,y = t.pos()
  if(x<-200):
    t.setheading(random.randint(280,440))
  if(x>200):
    t.setheading(random.randint(100,260))
  if(y<-200):
    t.setheading(random.randint(10,170))
  if(y>200):
    t.setheading(random.randint(190,350))