save project

my_tree.py

 import turtle
 import turtle
+import random
 def tree(n):
 def tree(n):
-    if n >=10:
+    if n >=0:
+        pen.pensize(n/10)
         pen.forward(n)
         pen.forward(n)
-        pen.right(30)
-        tree(n-0.1)
-        pen.left(60)
-        tree(n-0.1)
-        pen.right(30)
+        angle = random.randint(0,30)#随机角度
+        lenth = random.randint(1,15)
+        pen.right(angle)
+        tree(n-lenth)
+        pen.left(2*angle)
+        tree(n-lenth)
+        pen.right(angle)
         pen.up()
         pen.up()
         pen.backward(n)
         pen.backward(n)
         pen.down()
         pen.down()
@@ -21,5 +25,5 @@ pen.left(90)
 pen.up()
 pen.up()
 pen.backward(150)    # 后退
 pen.backward(150)    # 后退
 pen.down()
 pen.down()
-tree(100)
+tree(50)
 turtle.done()
 turtle.done()