一些杂碎的知识

import pandas as pd
import numpy as np
import pymysql 
#连接数据库，这里是连接自己的本地数据库
connect = pymysql.connect(host=‘127.0.0.1‘,port=3300,db=‘aaa‘,user=‘root‘,password=‘jiegege‘,charset=‘utf8‘)
data = pd.read_sql(‘select * from all_gzdata ‘,connect)

import numpy as np
np.set_printoptions(suppress=True)

np.linalg.inv(a)
np.dot(a,b)