save project

my_tree.py

 import turtle
-
+import random
 pen = turtle.Turtle()
-pen.color('sienna')
+pen.color('green')
 # 画布大小
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
@@ -12,17 +12,34 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 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(n/3)
+        else:
+            pen.color('green')
+            pen.pensize(n/10)
         pen.forward(n)
-        pen.right(30)
-        tree(n-50)
-        pen.left(60)
-        tree(n-50)
-        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()
-        
-        
-tree(200)
+pen = turtle.Turtle()
+pen.color('green')
+# 画布大小
+w = turtle.Screen()
+w.bgcolor('wheat')        
+pen.left(90)
+pen.up()
+pen.backward(150)
+pen.down        
+tree(60)
 turtle.done()