save project

my_tree.py

@@ -5,17 +5,21 @@ pen.color('sienna')
 # 画布大小
 # 画布大小
 w = turtle.Screen()
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
 w.bgcolor('wheat')      # wheat小麦
+pen.left(90)
+pen.up()
+pen.backward(150)    # 后退
+pen.down()
+pen.forward(150)
+# 移动到起点
 def tree(a):
 def tree(a):
- if a>=50: 
-        
-    pen.forward(a)
-    pen.backward(a)
-    pen.left(60)
-    tree(a-10)
-    pen.forward(a)
-    pen.backward(a)
-    pen.right(30)
-    tree(a-10)
-    pen.backward(a)
-tree(100)
+    if a>=50:      
+        pen.forward(a)
+        pen.right(30)
+        tree(a-50)
+        pen.left(60)
+        tree(a-50)
+        pen.right(30)
+        pen.backward(a)
+        return(a)
+tree(150)
 turtle.done()
 turtle.done()