save project

my_tree.py

 import turtle
-
+import random
 pen = turtle.Turtle()
 pen.color('sienna')
 # 画布大小
@@ -12,15 +12,25 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 def tree(a):
-    if a >= 50:
+    if a >= 0:
+        if a<=12:
+            color_list = ["snow","lightcoral"]
+            color = random.choice(color_list)
+            pen.color(color)
+            pen.pensize(a/3)
+        else:
+            pen.color("sienna")
+            pen.pensize(a/10)
         pen.forward(a)
-        pen.right(30)
-        tree(a-10)
-        pen.left(60)
-        tree(a-10)
-        pen.right(30)
+        angle = random.randint(25,30)
+        lenght = random.randint(10,15)
+        pen.right(angle)
+        tree(a-lenght)
+        pen.left(2*angle)
+        tree(a-lenght)
+        pen.right(angle)
         pen.up()
         pen.backward(a)
         pen.down()
-tree(100)
+tree(60)
 turtle.done()