save project

my_tree.py

-import turtle
-
-pen = turtle.Turtle()
+import turtle,random
+pen = turtle.Pen()
 pen.color('sienna')
 pen.color('sienna')
-# 画布大小
 w = turtle.Screen()
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
 w.bgcolor('wheat')      # wheat小麦
 
 
 # 移动到起点
 # 移动到起点
-pen.left(90)
+pen.setheading(90)
 pen.up()
 pen.up()
 pen.backward(150)    # 后退
 pen.backward(150)    # 后退
 pen.down()
 pen.down()
-
+pen.speed(0)
 def tree(n):
 def tree(n):
-    if n>=50:
+    if n>=0:
+        if n<=15:
+            c=random.choice(["snow","lightcoral"])
+            pen.pencolor(c)
+            pen.pensize(5)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        angle=random.randint(1,30)
+        length=random.randint(1,15)
         pen.forward(n)
         pen.forward(n)
-        pen.right(30)
-        tree(n-90)
-        pen.left(60)
-        tree(n-90)
-        pen.right(30)
+        pen.right(angle)
+        tree(n-length)
+        pen.left(angle*2)
+        tree(n-length)
+        pen.right(angle)
         pen.penup()
         pen.penup()
         pen.backward(n)   
         pen.backward(n)   
         pen.pendown()
         pen.pendown()
-tree(150)
-
-
-'''pen.forward(100)
-pen.right(30)
-pen.forward(50)
-pen.backward(50)
-pen.left(60)
-pen.forward(50)
-
-pen.left(-20)
-pen.up()
-pen.backward(150)    # 后退
-pen.down()'''
-
+tree(60)
 turtle.done()
 turtle.done()
-