auto save

oo。py

+import turtle
+import turtle
+import random
+pen = turtle.Turtle()
+pen.color('sienna')
+# 画布大小
+pen.pensize(6)
+w = turtle.Screen()
+w.bgcolor('black')      
+
+# 移动到起点
+pen.left(90)
+pen.up()
+pen.backward(150)    # 后退
+pen.down()
+
+def tree(n):
+    if n>=0:
+        a=random.randint(0,30)
+        b=random.randint(0,15)
+        pen.forward(n)
+        pen.right(a)
+        tree(n-b)
+        pen.left(2*a)
+        tree(n-b)
+        pen.right(a)
+        pen.penup()
+        pen.backward(n)
+        pen.pendown()
+tree(60)
+
+turtle.done()  
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