save project

my_tree.py

 import turtle
-
+import random
 def tree(n):
-   if n >= 50: 
+   if n >= 0:
+        a = random.randint(5,30)
+        b = random.randint(1,15)
+        if n <= 12:
+            c = random.choice(["snow","lightcoral"])
+            pen.color(c)
+            pen.pensize(n/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)
+        pen.right(a)
+        tree(n-b)
+        pen.left(2*a)
+        tree(n-b)
+        pen.right(a)
         pen.up()
         pen.backward(n)
         pen.down()
-
 pen = turtle.Turtle()
 pen.color('sienna')
 # 画布大小
@@ -23,5 +31,6 @@ pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
-tree(100)
+pen.speed(0)
+tree(60)
 turtle.done()