对python应用的一个巩固，以及熟悉matplotlib的用法

效果如下：

# -*- coding: utf-8 -*-

"""

Created on Fri Sep 28 22:39:55 2018

@author: pprp

"""

from random import choice

import matplotlib.pyplot as plt

class RandomWalk():

    """a class using to generate random data"""

    def __init__(self,num_points=5000):

        """init the class"""

        self.num_points=num_points

        # start at (0,0)

        self.x_val=[0]

        self.y_val=[0]

    def fill_walk(self):

        """calculate the points"""

        while len(self.x_val) < self.num_points:

            x_direction=choice([1,-1])

            x_distance=choice([0,1,2,3,4,5])

            x_step = x_direction * x_distance

            y_direction=choice([1,-1])

            y_distance=choice([1,2,5,4,0])

            y_step = y_direction * y_distance

            if x_step == 0 and y_step == 0:

                continue

            next_x = self.x_val[-1]+x_step

            next_y = self.y_val[-1]+y_step

            self.x_val.append(next_x)

            self.y_val.append(next_y)

rw = RandomWalk(50000)

rw.fill_walk()

plt.tick_params(axis='both',labelsize=14)

point_nums=list(range(rw.num_points))

plt.scatter(rw.x_val,rw.y_val,s=1,c=point_nums,cmap=plt.cm.Blues,edgecolors='none')

# plot the start point and end point

plt.scatter(0,0,c='green',edgecolors='none',s=100)

plt.scatter(rw.x_val[-1],rw.y_val[-1],c='red',edgecolors='none',s=100)

# set figure width and height

plt.figure(dpi=1280,figsize=(10,6))

plt.show()