save project

my_tree.py

+import random
+import turtle
+
+pen = turtle.Turtle()
+pen.color('sienna')
+# 画布大小
+w = turtle.Screen()
+w.bgcolor('wheat')      # wheat小麦
+def tree(n):
+    if n>=0:
+        if n<12:
+            pen.pencolor("red")
+            pen.pensize(n/2)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        leng=random.randint(5,15)
+        angle=random.randint(5,30)
+        pen.down()
+        pen.forward(n)
+        pen.right(angle)
+        tree(n-leng)
+        pen.left(2*angle)
+        tree(n-leng)
+        pen.right(angle)
+        pen.backward(n)
+        pen.penup()
+pen.left(90)
+pen.up()
+pen.backward(150)    # 后退
+pen.down()
+tree(60)
+turtle.done()