save project

my_tree.py

 import turtle
+import random
+old=input('请输入树龄:')
+def tree(n):
+    if n>=0:
+        if n<=12:
+            colour=['snow','lightcoral','lightcoral']
+            color=random.choice(colour)
+            pen.color(color)
+            pen.pensize(n/3)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        pen.forward(n)
+        angle=random.random()
+        pen.right(30*angle)
+        length=1.5*random.random()
+        tree(n-10*length)
+        pen.left(60*angle)
+        tree(n-10*length)
+        pen.right(30*angle)
+        pen.up()
+        pen.backward(n)
+        pen.down()
 pen = turtle.Turtle()
 pen.color('sienna')
 # 画布大小
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
 # 移动到起点
-pen.speed(400000000)
 pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
 
-pen.forward(100)
-pen.right(30)
-pen.forward(50)
-pen.backward(50)
-pen.left(60)
-pen.forward(50)
-pen.backward(50)
-pen.right(30)
-pen.backward(100)
+tree(old)
 turtle.done()