save project

my_tree.py

 import turtle
+import random
+
+coas =  ['snow','lightcoral']
 
 pen = turtle.Turtle()
 pen.color('sienna')
@@ -6,18 +9,34 @@ pen.color('sienna')
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
 
+def tree(n):
+    if n>=0:
+        ccd = random.randint(1,15)
+        if n-ccd <= 12:
+            pen.color(random.choice(coas))
+            pen.pensize(n/3)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        atre = random.randint(5,30)
+        pen.forward(n)
+        pen.down()
+        pen.right(atre)
+        tree(n-ccd)
+        pen.up()
+        pen.left(atre*2)
+        pen.down()
+        tree(n-ccd)
+        pen.right(atre)
+        pen.up()
+        pen.backward(n)
+
 # 移动到起点
+pen.speed(0)
 pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
-pen.forward(100)
-pen.right(30)
-pen.forward(50)
-pen.up()
-pen.backward(50)
-pen.down()
-pen.left(60)
-pen.forward(50)
+tree(60)
 
 turtle.done()