save project

my_tree.py

 import turtle
-
+import random
 pen = turtle.Turtle()
 pen.color('sienna')
 # 画布大小
@@ -11,17 +11,28 @@ pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
-pen.forward(100)
-pen.right(30)
-pen.forward(50)
-pen.penup()
-pen.backward(50)
-pen.left(60)
-pen.pendown()
-pen.forward(50)
-pen.penup()
-pen.backward(50)
-pen.right(30)
-pen.backward(100)
-pen.pendown()
+def tree(n):
+    if n>=0:
+        if n<=12:
+            q=['snow','lightcoral']
+            c=random.choice(q)
+            pen.color(c)
+            pen.pensize(n/3)
+        else:
+            pen.color('sienna') 
+            pen.pensize(n/10)
+        a=random.randint(0,30)
+        l=random.randint(1,15)
+        pen.forward(n)
+        pen.right(a)
+        tree(n-l)
+        pen.left(2*a)
+        tree(n-l)
+        pen.right(a)
+        pen.up()
+        pen.backward(n)
+        pen.down()
+tree(60)
+tree(60)
+tree(60)
 turtle.done()