turtle-graphics：我在使用按键缩小和增大海龟时遇到问题

Question

我写了一段代码，可以让乌龟在盒子里四处移动。如果您按下某些键，例如 g 表示增长，s 表示收缩，我正在尝试编写一部分来更改其大小。但是，我觉得我让它变大变小的方式不是很好。每当乌龟处于默认大小并且我按下收缩时，我都会收到一条错误消息，指出它的 stetch_len/stretch_wid 不能是 0.

我已经尝试使用 if 来制作它，因此如果它的大小为 1，它就不会缩小，但我无法让它工作。我觉得可能和我缩小的方法有关系，但我不确定。

半相关，我设置了一个按钮，可以在按下时将乌龟重置为默认值。但是，如果我让乌龟变大，它就不会缩小那么多。我做得越大，它的默认值似乎就越大。同样，我认为这与我使用的更改大小的方法有关，但我不确定。

import turtle
import os

#Creates the window for the game
wn = turtle.Screen()
wn.bgcolor("cyan")
wn.title("Game Test")

#Creates the background for the game
border_pen = turtle.Turtle()
border_pen.speed(0)
border_pen.color("black")
border_pen.penup()
border_pen.setposition(-250,-250)
border_pen.pendown()
border_pen.pensize(1)
for side in range(4):
    border_pen.fd(500)
    border_pen.lt(90)
border_pen.hideturtle()

#Creates the turtle
player = turtle.Turtle()
player.color("black")
player.shape("square")
player.pensize(2)
#player.penup()
player.setposition(0, 0)
player.setheading(90)
player.shapesize(1)

playerspeed = 10



# This resets the player to its default, beginning state
def reset():
    player.setposition(0, 0)
    player.setheading(90)
    player.shapesize(1)


# Makes the character grow larger
def grow():
    size = player.turtlesize()
    increase = tuple([1 + num for num in size])
    player.turtlesize(*increase)
    return

#Makes the character shrink
def shrink():
    size = player.turtlesize()
    decrease = tuple([-1 + num for num in size])
    if player.turtlesize() == 1:
        return
    else:
        player.turtlesize(*decrease)
    return

# Prints the characters coordinates in a seperate window from the game
def place():
    b, c = player.pos()
    print("\n")
    print(b, ",", c)


# These are the keys you push to activate different things
# The movement uses a number pad, which make programming diagonal keys easier.
turtle.listen()
turtle.onkeypress(reset, "5")
turtle.onkey(grow, "g")
turtle.onkey(shrink, "s")
turtle.onkey(place, "p")


input("Press any key to exit...")

Answer 1

Uriya Harpeness 引起了我的注意，我正在使用 turtlesize。我将其切换为 shapesize，这样我就可以更正代码。

为了解决这个问题，我使用了 shapesize 并将变量设置为 a、b、c 而不是大小。这让我可以添加到每个值，然后将新值设置为 shapesize.

也是reset函数的意思，我只需要写player.shapesize(1, 1, 1)。

#Makes the character shrink
def shrink():
    a, b, c = player.shapesize()
    if a > 1:
        a = a - 1
        b = b - 1
        c = c - 1
        player.shapesize(a, b, c)
        print(a, b, c)
    else:
        print(a, b, c)
        return

turtle-graphics：我在使用按键缩小和增大海龟时遇到问题

turtle-graphics: I am having trouble using keys to shrink and grow the turtle

python

python-turtle