save project

my_tree.py

+import turtle
+import random
+
+
+pen = turtle.Turtle()
+pen.color('sienna')
+pen.speed(0)
+# 画布大小
+w = turtle.Screen()
+w.bgcolor('wheat')      # wheat小麦
+
+# 移动到起点
+pen.left(90)
+pen.up()
+pen.backward(150)    # 后退
+pen.down()
+
+
+
+def tree(n):
+    if n>=0:
+        if n<=12:
+            lest=['black','red']
+            pen.pensize(n/3)
+            color=random.choice(lest)
+            pen.color(color)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        a=1.5*random.random()    
+        pen.forward(n)
+        b=random.random()
+        pen.right(30*b)
+        tree(n-10*a)
+        pen.left(60*b)
+        tree(n-10*a)
+        pen.right(30*b)
+        pen.up()
+        pen.backward(n)
+        pen.down()
+
+   
+tree(60)
+turtle.done()