auto save

my_tree.py

 import turtle
+import random
 
 pen = turtle.Turtle()
 pen.color('sienna')
 # 画布大小
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
-
+pen.speed(0)
 # 移动到起点
 pen.left(90)
 pen.up()
@@ -13,7 +14,26 @@ pen.backward(150)    # 后退
 pen.down()
 
 def tree(n):
-    pen.forward(n)
-    pen.right(30)
-    tree(n-50)
-turtle.done()
+    if n>=0:
+        if n <=12:
+            coler_list=['snow','lightcoral']
+            coler=random.choice(coler_list)
+            pen.color(coler)
+            pen.pensize(n/3)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        pen.forward(n)
+        angle=random.random()
+        pen.right(30*angle)
+        length=1.5*random.random()
+        tree(n-10*length)
+        pen.left(60*angle)
+        tree(n-10*length)
+        pen.right(30*angle)
+        pen.up()
+        pen.backward(n)
+        pen.down()
+
+tree(60)
+turtle.done()
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