python - turtle 和 turtle 有什么区别？

Question

Python 2.7 版本中的 turtle 和 Turtle 有何不同？

import turtle
star = turtle.Turtle()
for i in range(50):
    star.forward(50)
    star.right(144)
turtle.done()

Answer 1

turtle 模块很不寻常。为了让新手程序员更容易上手，Turtle 类的所有方法也可用作对默认(未命名)turtle 实例进行操作的顶级函数。 Screen 类的所有方法也可用作在默认(唯一)屏幕实例上运行的顶级函数。所以这两个:

import turtle

star = turtle.Turtle()  # turtle instance creation

for i in range(5):
    star.forward(50)  # turtle instance method
    star.right(144)  # turtle instance method

screen = turtle.Screen()  # access sole screen instance
screen.mainloop()  # screen instance method

还有这个:

import turtle

for i in range(5):
    turtle.forward(50)  # function, default turtle
    turtle.right(144)

turtle.done()  # function, mainloop() synonym, acts on singular screen instance

都是有效的实现。许多 turtle 程序最终将函数接口(interface)与对象接口(interface)混合在一起。为了避免这种情况，我强烈建议使用以下导入语法:

from turtle import Turtle, Screen

这会强制对象方法使用turtle，从而使函数方法不可用:

from turtle import Turtle, Screen

star = Turtle()  # turtle instance creation

for i in range(5):
    star.forward(50)  # turtle instance method
    star.right(144)  # turtle instance method

screen = Screen()  # access sole screen instance
screen.mainloop()  # screen instance method