import turtle
tess = turtle.Turtle()
wn = turtle.Screen()
def hello3 (x,y):
tess.goto(x, y)
return tess.xcor()
我希望我的函数hello3在我点击屏幕上的某个地方后返回我的乌龟的x坐标,但它似乎总是返回None。
turtle.onscreenclick(hello3, btn=1)
答案 0 :(得分:0)
当你打电话给turtle.onscreenclick(hello3,btn = 1)时,它会绑定' hello3'功能到屏幕点击事件。但是,它不会调用' hello3'立即运作。当有一个屏幕点击事件时,程序将调用' hello3'功能。因此,turtle.onscreenclick()返回None,因为它将函数连接到事件但不调用该函数。请尝试以下代码:
import turtle
tess = turtle.Turtle()
wn = turtle.Screen()
def hello3(x,y):
tess.goto(x, y)
# When you click the screen, it will print out its x-coordinate.
print tess.xcor()
# You cannot receive this return value, if you put this function
# as a call-back function (or completion handler).
return tess.xcor()
returnValue = turtle.onscreenclick(hello3, btn=1)
print type(returnValue)
turtle.done()