Python Turtle如何编程使其自动关闭？

Question

I have to program a function that draws triangles. I managed to draw triangles next to each other quite well, but I can't program it in such a way that the triangles stand one under the other. Or at least not that it goes automatically.
I did it like that:

import turtle
otto = turtle.Turtle()

def triangle(t, l): 
    t.color("cadetblue")
    t.begin_fill() 
    for i in range(3):
        t.fd(l)
        t.lt(360/3)
    t.end_fill() 

def pile_triangle (t,l):
    for i in range(1):
        triangle(t, l)
        t.penup()
        t.goto(0,-70)
        t.pendown()
    for i in range(1):  
        triangle(t, l) 
        t.penup()
        t.goto(0,-140)
        t.pendown()
    for i in range(1): 
        triangle(t, l) 
        t.penup()
        t.goto(0,-210)
        t.pendown()
    for i in range(1):  
        triangle(t, l) 


otto = turtle.Turtle()
pile_triangle(otto, 80)


turtle.mainloop()
turtle.bye()

So, as you can see, when the value of l increases, there are gaps or triangles overlap. Can it be done differently? So that it draws four triangles and matches the length l?

Answer 1

Is this what you want?

import turtle
def triangle(t,l): 
    t.color("cadetblue")
    t.begin_fill() 
    t.lt(360/6)
    for i in range(3):
        t.lt(-360/3)
        t.fd(l)
    t.end_fill()
    t.penup()
    t.lt(-360/3)
    t.fd(l)
    t.lt(-360/3)
    t.fd(l/2)
    t.lt(180)
otto = turtle.Turtle()
for i in range(3):
    triangle(otto,50)

Answer 2

Your original code is pretty close, you only need a couple of things: Thing 1 is to turn your repeated code pattern into a loop. Thing 2 is to calculate the amount to move (the triangle's height) rather than use a fixed value. From trigonometry you recall that the height of an equilateral triangle is:

side_length * sqrt(3) / 2

Here's a rework of your code with these two changes:

import turtle

def triangle(t, length):
    t.begin_fill()

    for i in range(3):
        t.forward(length)
        t.left(360 / 3)

    t.end_fill()

def pile_triangle(t, length):
    height = length * 3 ** 0.5 / 2  # height of triangle given a side

    for i in range(1, -3, -1):  # center stack vertically on screen
        t.penup()
        t.goto(-length / 2, i * height)  # center stack horizontally on screen
        t.pendown()

        triangle(t, length)

otto = turtle.Turtle()
otto.color("cadetblue")

pile_triangle(otto, 100)

turtle.mainloop()
turtle.bye()