save project

my_tree.py

 import turtle
 import turtle
-
+import random
 pen = turtle.Turtle()
 pen = turtle.Turtle()
 pen.color('sienna')
 pen.color('sienna')
 # 画布大小
 # 画布大小
@@ -11,5 +11,29 @@ pen.left(90)
 pen.up()
 pen.up()
 pen.backward(150)    # 后退
 pen.backward(150)    # 后退
 pen.down()
 pen.down()
-
+pen.left(60)
+pen.ward(150)
 turtle.done()
 turtle.done()
+#树枝
+def tree(n):
+    if n>0:
+        if n<=12:
+            color_list=['snow','lightcoral']
+            color=random.choice(color_list)
+            pen.color(color)
+            pen.penpensize(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)
+        pen.up()
+        pen.backward(n)
+        pen.down()
+
+
+