nested-for-loop - 使用 trinket.io 嵌套 For 循环

Question

我开始在 trinket.io 上做这个关于绘制雪花的练习，我不太了解循环中的步骤（特别是内循环完成的地方）的顺序。我将非常感谢您的帮助。谢谢！ 在此处输入图像描述

#!/bin/python3
import turtle
#starts the software that allows you to draw
import random
# starts the software that provides randomness
orange = turtle.Turtle()
#naming my turtle by associating it with a variable


turtle.Screen().bgcolor("black")
#sets the screen colour to black
colours = ["cyan","purple","white","blue"]
orange.color(random.choice(colours))
#using the random function the program will choose from the list of colours

orange.penup() # moves pen without writing
orange.forward(90) # moves 90 units forward
orange.left(45) #does an angle of 45 anticlockwise (going left)
orange.pendown() #starts drawing


def branch():
for i in range(3):  
    for i in range(3):
        orange.forward(30) 
        orange.backward(30) 
        orange.right(45) 
    orange.left(90) 
    orange.backward(30) 
    orange.left(45) 
orange.right(90)
orange.forward(90)

for i in range(8):
    branch()
    orange.left(45)