import turtle
pen = turtle.Pen()
pen.forward(100) # 向前走100
pen.right(90)  # 向右转90度
pen.forward(100) # 向前走100
pen.right(90)  # 向右转90度
pen.forward(100) # 向前走100
pen.right(90)  # 向右转90度
pen.forward(100) # 向前走100
pen.right(90)  # 向右转90度