我的程序
import turtle
i = "input()"
while i == "input()":
if i == "exit":
input()
if i == "fd":
turtle.fd(1)
if i == "bk":
turtle.bk(1)
if i == "lt":
turtle.lt(90)
if i == "rt":
turtle.rt(90)
if i == "pu":
turtle.pu()
if i == "pd":
turtle.pd()
现在我输入的文件是 (fd,fd,fd,bk,bk,lt,rt 等) 它应该画一个正方形但没有显示我做错了什么