save project

my_tree.py

 import turtle
+import random
 
 pen = turtle.Turtle()
 pen.color('sienna')
@@ -12,17 +13,26 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 def tree(n):
-    if n>=50:
-        pen.forward(n)
-        pen.right(30)
-        tree(n-50)
-        pen.left(60)
-        tree(n-50)
-    
-        pen.right(30)
+    if n >= 0:
+        if n <= 12:
+            color_list = ['snow','lightcoral']
+            color = random.choice(color_list)
+            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.up()
         pen.backward(n)
         pen.down()
-tree(200)
+            
+tree(60)
 
 turtle.done()