Python趣味挑战之turtle库绘画飘落的银杏树

def Fibonacci_Recursion_tool(n):  #斐波那契数列方法
 if n <= 0:
  return 0
 elif n == 1:
  return 1
 else:
  return Fibonacci_Recursion_tool(n - 1) + Fibonacci_Recursion_tool(n - 2)
def Fibonacci_Recursion(n):  #生成斐波那契数列，并存入列表
 result_list = []
 for i in range(1, n + 3):
  result_list.append(Fibonacci_Recursion_tool(i))
 return result_list

yu = Fibonacci_Recursion(top)  #生成斐波契那数列
print(yu)

def leaf(x, y, node):#定义画叶子的方法
 til = turtle.heading()
 i = random.random()
 an = random.randint(10, 180)
 ye = random.randint(6, 9)/10
 turtle.color(ye, ye*0.9, 0)
 turtle.fillcolor(ye+0.1, ye+0.05, 0)
 turtle.pensize(1)
 turtle.pendown()
 turtle.setheading(an + 90)
 turtle.forward(8*i)
 px = turtle.xcor()
 py = turtle.ycor()
 turtle.begin_fill()
 turtle.circle(7.5*i, 120)  # 画一段120度的弧线
 turtle.penup()  # 抬起笔来
 turtle.goto(px, py)  # 回到圆点位置
 turtle.setheading(an + 90)  # 向上画
 turtle.pendown()  # 落笔，开始画
 turtle.circle(-7.5*i, 120)  # 画一段120度的弧线
 turtle.setheading(an + 100)
 turtle.circle(10.5*i, 150)
 turtle.end_fill()  # 画一段150度的弧线
 turtle.penup()
 turtle.goto(x, y)
 turtle.setheading(til)
 turtle.pensize(node / 2 + 1)

def draw(node, length, level, yu, button):  #定义画树的方法
 turtle.pendown()
 t = cos(radians(turtle.heading()+5)) / 8 + 0.25
 turtle.pencolor(t*1.6, t*1.2, t*1.4) #(r, g, b)颜色对应的RGB值
 turtle.pensize(node/1.2)  #画笔的尺寸
 x = random.randint(0, 10)  #生成随机数决定要画树枝还是画飘落的叶子
 if level == top and x > 6:  #此时画飘落的叶子，x范围太大会导致树太秃
  turtle.forward(length)  # 画树枝
  yu[level] = yu[level] - 1
  c = random.randint(2, 10)
  for i in range(1, c):
leaf(turtle.xcor(), turtle.ycor(), node)
  # 添加0.3倍的飘落叶子
if random.random() > 0.3:
 turtle.penup()
# 飘落
 t1 = turtle.heading()
 an1 = -40 + random.random() * 40
 turtle.setheading(an1)
 dis = int(800 * random.random() * 0.5 + 400 * random.random() * 0.3 + 200 * random.random() * 0.2)
 turtle.forward(dis)
 turtle.setheading(t1)
 turtle.right(90)
# 画叶子
 leaf(turtle.xcor(), turtle.ycor(), node)
 turtle.left(90)
# 返回
 t2 = turtle.heading()
 turtle.setheading(an1)
 turtle.backward(dis)
 turtle.setheading(t2)
 elif level==top and x < 7 : #此时画枝叶，x范围太大会导致飘落的叶子太少
  turtle.penup()
  turtle.forward(length)
 elif level>3 and (x>6) :#三级树枝以上，有40%的概率执行以下策略
  turtle.pendown()
  turtle.forward(length)
  c = random.randint(4, 6)
  for i in range(3, c):
leaf(turtle.xcor(), turtle.ycor(),node)
  leaf(turtle.xcor(), turtle.ycor(),node)
  button=1# jump"""
 else:
  turtle.forward(length)  # 画树枝
  yu[level] = yu[level] -1
 if node > 0 and button == 0:
  # 计算右侧分支偏转角度,在固定角度偏转增加一个随机的偏移量
  right = random.random() * 5 + 17
  # 计算左侧分支偏转角度,在固定角度偏转增加一个随机的偏移量
  left = random.random() * 20 + 19
  # 计算下一级分支的长度
  child_length = length * (random.random() * 0.25 + 0.7)
  # 右转一定角度,画右分支
  r=random.randint(0, 1)
  if r==1:
 turtle.right(right)
 level = level + 1
 #print("level", level)
  else:
 turtle.left(right)
 level = level + 1
 #print("level", level)
  draw(node - 1, child_length,level,yu,button)
  yu[level] = yu[level] +1
  if yu[level] > 1:
# 左转一定角度，画左分支
if r==1:
turtle.left(right + left)
draw(node - 1, child_length, level, yu,button)
# 将偏转的角度，转回
turtle.right(left)
yu[level] = yu[level] - 1
else:
 turtle.right(right + left)
 draw(node - 1, child_length, level, yu,button)
 # 将偏转的角度，转回
 turtle.left(left)
 yu[level] = yu[level] - 1
  else:
if r==1:
  turtle.left(right + left)
  turtle.right(left)
else:
 turtle.right(right + left)
 turtle.left(left)
 turtle.penup()
 #退回到上一级节点顶部位置
 turtle.backward(length)
 
5.主函数部分
主函数中直接调用上述函数就行，top控制树的高度，turtle.speed控制画的速度，最后的turtle.write（）用来书写最下方的签名。
```clike
if __name__ == '__main__':
 turtle.setup(width=1.0, height=1.0) #设置全屏显示
 turtle.hideturtle()  # 隐藏turtle
 turtle.speed(0)  # 设置画笔移动的速度，0-10 值越小速度越快
 # turtle.tracer(0,0)#设置动画的开关和延迟，均为0
 turtle.penup()  # 抬起画笔
 turtle.left(90)  # 默认方向为朝x轴的正方向，左转90度则朝上
 turtle.backward(300)  # 设置turtle的位置，朝下移动300
 top = 9  #树高
 yu = Fibonacci_Recursion(top)  #生成斐波契那数列
 yu.remove(yu[0])
 #print(yu) 打印斐波那契数列
 button = 0
 draw(top, 120, 0, yu, button)  # 调用函数开始绘制
 turtle.write("wsw", font=("微软雅黑", 14, "normal")) #生成签名
 turtle.done()