python matplotlib从文件中读取数据绘制折线图

说明：从文件中读取数据，绘制直线图

#coding:utf-8
import matplotlib.pyplot as plt
import matplotlib as mpl
import numpy as np
from matplotlib.font_manager import FontProperties
import matplotlib as mpl
mpl.rcParams['font.family'] = 'sans-serif'
mpl.rcParams['font.sans-serif'] = 'NSimSun,Times New Roman'


x, y = np.loadtxt('难度30.txt', delimiter=',', unpack=True)
plt.plot(x,y,label='难度值为30',color='black')
plt.plot(x,y,'o',color='black')

plt.xlabel('XXXX')
plt.ylabel('XXXX')

plt.title(u'XXXXXX')
plt.legend()
plt.show()
#coding:utf-8
import mat