一、递归参数的使用

用递归来从1写到100
先定义一个函数并将其参数命名为a和b
注意递归的出口要在递归之前

#输出a-b之间所有的整数
def text(a,b):if a > b :returnprint(a)text(a+1,b)
text(1,100)

二、分形树

成品

源码：

import turtle
pen = turtle.Turtle()
turtle.colormode(255)
pen.speed(0)
r = 0
g = 0
b = 0
#树干
#树干的长度
length = 120
#画笔的粗细
pen_size=14
pen.pensize(pen_size)
pen.penup()
pen.left(90)
pen.backward(length)
pen.pendown()
pen.forward(length)
#树枝
def draw_tree(l,lv):#lv决定进行多少次递归l = l*3/4size = pen.pensize()pen.pensize(size*3/4)global r,g,b#引入变量r += 1g += 2b += 3pen.pencolor(r%200,g%200,b%200)#限制颜色范围#左边枝干的递归pen.left(45)pen.forward(l)#左边枝干的递归if lv < 14:draw_tree(l,lv+1)pen.backward(l)pen.right(90)#右边枝干pen.forward(l)if lv < 14:draw_tree(l,lv+1)pen.backward(l)pen.left(45)pen.pensize(size)
draw_tree(length,4)
turtle.done()