save project

my_tree.py

-import turtle
+import turtle,random
+
+def tree(n):
+    if n>=0:
+        if n<=12:
+            color_list = ['snow','lightcoral']
+            color = random.choice(color_list)
+            pen.color(color)
+            pen.pensize(n/3)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        pen.forward(n)
+        angle = random.randint(0,30)
+        leng = random.randint(1,15)
+        pen.right(angle)
+        tree(n-leng)
+        pen.left(2*angle)        
+        tree(n-leng)
+        pen.right(angle)
+        pen.up()
+        pen.backward(n)
+        pen.down()
 
 pen = turtle.Turtle()
 pen.color('sienna')
 # 画布大小
 w = turtle.Screen()
-w.bgcolor('wheat')      # wheat小麦
+w.bgcolor('white')      # wheat小麦
 
 # 移动到起点
 pen.left(90)
@@ -12,18 +34,7 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 
-pen.forward(100)
-pen.right(30)
-pen.forward(50)
-pen.up()
-pen.down()
-pen.backward(50)
-pen.left(60)
-pen.forward(50)
-pen.up()
-pen.backward(50)
-pen.left(150)
-pen.forward(100)
+tree(100)