from random import choice
 
class RandomWalk():
 "一个生成随机漫步数据的表"
 
 def __init__(self, num_points = 5000):
 """初始化随机漫步的属性"""
 self.num_points = num_points
 
 # 所有随机漫步都起始于(0, 0)
 self.x_values = [0]
 self.y_values = [0]
 
 def fill_walk(self):
 """计算随机漫步包含的所有点"""
 
 # 不断漫步，直到列表达到指定的长度
 while len(self.x_values) < self.num_points:
 
  # 决定前进的方向以及沿这个方向前进的距离
  x_direction = choice([-1, 1])
  x_distance = choice([0, 1, 2, 3, 4])
  x_step = x_distance * x_direction 
 
  y_direction = choice([-1, 1])
  y_distance = choice([0, 1, 2, 3, 4])
  y_step = y_distance * y_direction
 
  # 拒绝原地踏步
  if x_step == 0 and y_step == 0:
  continue
 
  # 计算下一个点的x和y值
  next_x = self.x_values[-1] + x_step
  next_y = self.y_values[-1] + y_step
 
  self.x_values.append(next_x)
  self.y_values.append(next_y)

from random_walk import RandomWalk
 
# 不断的模拟随机漫步
while True:
 # 创建一个RandomWalk实例，将其包含的点绘制出来
 rw = RandomWalk()
 rw.fill_walk()
 
 
 point_numbers = list(range(rw.num_points))
 plt.scatter(rw.x_values, rw.y_values, c = point_numbers, cmap = plt.cm.Blues, 
 edgecolor = 'none', s = 5)
 
 # 突出起点和终点
 plt.scatter(0, 0, c='green', edgecolors = 'none', s = 100)
 plt.scatter(rw.x_values[1], rw.y_values[-1], c = 'red', edgecolors = 'none', s = 100)
 
 # 隐藏坐标轴
 # plt.axes().get_xaxis().set_visible(False)
 # plt.axes().get_yaxis().set_visible(False)
 
 plt.show()
 
 keep_running = input("Make another walk")
 if keep_running.lower().startswith('n'):
 break