python - 如何通过列表更改 Turtle 中形状的颜色

Question

我想知道是否有一种方法可以制作颜色列表，例如shape_color = ['red', 'blue', 'green']，并将该列表分配给单个onkey()键盘键，以便每当我按下该键时，它会在颜色列表中循环，改变海龟的颜色？我的程序是 Python 海龟图形，您可以在其中移动光标，将不同的形状印入屏幕。

Answer 1

shape_color = ['red', 'blue', 'green'] # list of colors
idx = 0 # index for color list

# Callback for changing color
def changecolor():
    idx = (idx+1) % len(shape_color) # Increment the index within the list bounds
    fillcolor(shape_color[idx]) # Change the fill color

# Register the callback with a keypress.
screen.onkey(changecolor, "c")

现在，每次您按下该c键时，您的填充颜色都会改变，在您定义的列表中循环。

Answer 2

@jfs 对 @Aesthete 示例的修复的完整版本：

from turtle import Screen, Turtle
from itertools import cycle

shape_colors = ['red', 'blue', 'green', 'cyan', 'magenta', 'yellow', 'black']

def change_color(colors=cycle(shape_colors)):
    turtle.color(next(colors))

turtle = Turtle('turtle')
turtle.shapesize(5)  # large turtle for demonstration purposes

screen = Screen()
screen.onkey(change_color, 'c')
screen.listen()
screen.mainloop()