save project

my_tree.py

 import turtle
-
+import random
 pen = turtle.Turtle()
+pen.speed(0)
+def tree(n):
+    if n >= 0:
+        if n <=12:
+            color_list=['snow','lightcoral']
+            pen.color(random.choice(color_list))
+            pen.pensize(n/3)
+        else:
+            pen.color('sienna')
+            pen.pensize(n/10)
+        pen.fd(n)
+        angle=random.randint(0,30)
+        length=random.randint(1,15)
+        pen.rt(angle)
+        tree(n-length)
+        pen.lt(2*angle)
+        tree(n-length)
+        pen.rt(angle)
+        pen.up()
+        pen.backward(n)
+        pen.down()
 pen.color('sienna')
 # 画布大小
 w = turtle.Screen()
@@ -11,5 +32,22 @@ pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
+tree(70)
+# pen.fd(100)
+# pen.rt(30)
+# pen.fd(50)
+# pen.up()
+# pen.backward(50)
+# pen.down()
+
+# pen.lt(60)
+# pen.fd(50)
+# pen.up()
+# pen.backward(50)
+# pen.down()
 
+# pen.rt(30)
+# pen.up()
+# pen.backward(100)
+# pen.down()
 turtle.done()