save project

my_tree.py

 import turtle
-def draw():
-    i = 100
-    y = 30
-    pen.fd(i)
-    pen.right(y)
-    pen.fd(i/2)
+def draw(n):
+    pen.speed(100)
+    if n >= 50:
+        pen.fd(n)
+        pen.right(30)
+        draw(n-10)
+        pen.left(60)
+        draw(n-10)
+        pen.right(30)
         pen.up()
-    pen.bk(i/2)
-    pen.down()
-    pen.left(y*2)
-    pen.fd(i/2)
-    pen.up()
-    pen.bk(i/2)
-    pen.down()
-    pen.right(y)
-    pen.up()
-    pen.bk(i)
+        pen.bk(n)
         pen.down()
 pen = turtle.Turtle()
 pen.color('sienna')
@@ -29,5 +23,5 @@ pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
-draw()
+draw(100)
 turtle.done()