save project

my_tree.py

+import turtle
+import random
+pen = turtle.Turtle()
+pen.color('sienna')
+# 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:
+            color_list=['snow','lightcoral']
+            color=random.choice(color_list)
+            pen.color(color)
+            pen.pensize(n / 3)
+        else:
+            pen.color('sienna')
+            pen.pensize(n / 10) 
+        pen.forward(n)
+        angle=random.random()
+        pen.right(30*angle)
+        length=1.5*random.random()
+        tree(n-10*length)
+        pen.left(60*angle)
+        tree(n-10*length)
+        pen.right(30*angle)
+        pen.up()
+        pen.backward(n)
+        pen.down()       
+tree(60)        
+turtle.done()
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