save project

my_tree.py

+import turtle
+import random
+pen = turtle.Turtle()
+# 画布大小
+w = turtle.Screen()
+w.bgcolor('wheat')    
+c=["snow","lightcoral"]
+def tree(n):
+    if n>10:
+        if n<=12:
+            pen.color(random.choice(c))
+            pen.pensize(n/3)
+        else:
+            pen.color("sienna")
+            pen.pensize(n/10)
+        b=random.randint(0,15)
+        a=random.randint(10,30)
+        pen.forward(n)
+        pen.right(a)
+        tree(n-b)
+        pen.left(2*a)
+        tree(n-b)
+        pen.right(a)
+        pen.up()
+        pen.backward(n)
+        pen.down()
+
+# 移动到起点
+pen.left(90)
+pen.up()
+pen.backward(150)    # 后退
+pen.down()
+
+tree(60)
+
+
+turtle.done()