python龟图形不绘制

Question

当我运行以下代码时，它只弹出一个窗口，不绘制任何图形。

我从参考文献中尝试了一些例子，但在所有情况下，它都发生了。 有人可以帮我解决问题吗？

import turtle
turtle.mainloop()
t = turtle.Turtle()
t.color('red')
t.pensize(10)
t.shape('turtle')

Answer 1

看这里：

https://docs.python.org/3.1/library/turtle.html#turtle.mainloop

启动事件循环 - 调用 Tkinter 的mainloop函数。 必须是海龟图形程序中的最后一条语句。 如果脚本以 -n 模式（无子进程）从 IDLE 内运行，则不得使用 - 用于海龟图形的交互使用。

所以你有第二行到你的程序结尾

同样没有主循环，我可以看到在 repl.it 中运行时绘制的红色海龟： https ://repl.it/@CarstenEggers/Raphael

Answer 2

它没有做任何事情的原因是因为你还没有真正告诉“画儿” t到画什么。 您告诉它要做的所有事情只是设置说明：使用什么颜色，绘制什么尺寸等。

尝试运行此代码。 评论中的解释：

import turtle
# turtle.mainloop()  # Generally not necessary to run mainloop; can just delete
t = turtle.Turtle()  # Creating a turtle to do drawing
t.color('red')  # Telling it what color to draw
t.pensize(10)  # Telling it what size to draw at
t.shape('turtle')  # What shape turtle draw-er should be: "arrow", "turtle", etc

# Now let's draw something!
t.forward(50)  # Tell turtle to draw in forward direction 50 pixels
t.left(80)  # Tell turtle to turn in-place 80 degrees to left
t.forward(100)  # Draw 100 pixels forward
t.right(90)  # Turn in-place 90 degrees right
t.forward(170)  # Draw 170 pixels forward
# Done drawing!

turtle.exitonclick()  # Tell program to keep picture on screen, exit on click
# Note: See how that's `turtle` and not `t`? That's because we don't want to
# tell our draw-er `t` anything: `t` is just for drawing, it doesn't control
# the larger scope of starting and exiting. If we said `t.exitonclick()`, the
# program would just break at the end, because the draw-er does not know how
# to exit or anything.
# On the the other hand, the module `turtle` (where we get the draw-er and
# everything else from) does know how to handle starting and exiting, so that's
# why we make the call to the module itself instead of the draw-er `t`.