save project

my_tree.py

 import turtle
+import random
 
 pen = turtle.Turtle()
 pen.color('sienna')
@@ -10,19 +11,28 @@ w.bgcolor('wheat')      # wheat小麦
 
 pen.left(90)
 pen.down()
-pen.backward(100)    # 后退
+pen.backward(90)    # 后退
 def tree(n):
-    if n>=50:
+    if n>=0:
+        if n<=12:
+            color_l=['snow','lightcoral']
+            pen.color(random.choice(color_l))
+            pen.pensize(n/3)
+        else:
+            pen.pencolor('sienna')
+            pen.pensize(n/10)
         pen.forward(n)
-        pen.right(30)
-        tree(n-10)
-        pen.left(60)
-        tree(n-10)
-        pen.right(30)
+        a=random.randint(0,30)
+        l=random.randint(1,15)
+        pen.right(a)
+        tree(n-l)
+        pen.left(2*a)
+        tree(n-l)
+        pen.right(a)
         pen.up()
         pen.backward(n)
         pen.down()
-tree(100)
+tree(60)
 
 
 turtle.done()