save project

diy2.py

 import turtle
+import random
 
 def tree(n):
-    if n >= 50:
+    if n >= 0:
+        if n<= 12:
+            color_list = ['snow','lightcoral']
+            color = random.choice(color_list)
+            pen.color(color)
+            pen.pensize(10/3)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
         pen.forward(n)
-        pen.right(30)
-        tree(n-10)
-        pen.left(60)
-        tree(n-10)
-        pen.right(30)
+        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()
@@ -15,13 +26,14 @@ pen = turtle.Turtle()
 pen.color('sienna')
 #画布大小
 w = turtle.Screen()
-w.bgcolor("wheat")
+w.bgcolor("sky blue")
 #移动到起点
 pen.left(90)
 pen.up
-pen.backward(100)
+pen.backward(150)
 pen.down
 
-tree(100)
+tree(70)
 turtle.done()
 
+