Python精灵模块的set_polar指令

from sprites import Sprite,Screen

screen = Screen()
screen.rt_grid()   # 显示极坐标

bug = Sprite()
# 120是角色到原点的距离，45是角度
bug.set_polar(120,45)
bug.wait(1)
for i in range(360):
    bug.set_polar(120,i)
    bug.set_heading(i)
    bug.wait(0.01)
screen.mainloop()