python读写mysql

• 读取mysql数据

  # -*- coding: utf-8 -*-
  # 导入必要模块
  import pandas as pd
  from sqlalchemy import create_engine
  # 初始化数据库连接，使用pymysql模块
  # MySQL的用户：root, 密码:147369, 端口：3306,数据库：mydb
  engine = create_engine('mysql+pymysql://root:123456@localhost:3306/student')
  
  # 查询语句，选出employee表中的所有数据
  sql = '''select * from data;'''
  # read_sql_query的两个参数: sql语句， 数据库连接
  df = pd.read_sql_query(sql, engine,index_col='index')
  # 输出employee表的查询结果
  print(df.shape)
  

  　　

• pandas写入数据库

  # coding:utf-8
  import pandas as pd
  from sqlalchemy import create_engine
  # 初始化数据库连接，使用pymysql模块
  # MySQL的用户：root, 密码:147369, 端口：3306,数据库：mydb
  engine = create_engine('mysql+pymysql://root:123456@localhost:3306/student')
  import datetime
  start = datetime.datetime.now().strftime('%Y-%m-%d')
  end = (datetime.datetime.now()+datetime.timedelta(days=100)).strftime('%Y-%m-%d')
  # 新建pandas中的DataFrame, 只有id,num两列
  # df = pd.DataFrame(data=np.random.randint(-100,100,(100,100)),index=pd.date_range('2018-1-1',periods=100,dtype='datetime64[ns]', freq='D'),columns=None,dtype=int)
  # print(df.shape)
  # 将新建的DataFrame储存为MySQL中的数据表，不储存index列
  # df.to_sql('data', engine, if_exists='append',index= True)
  
  def write_sql(name,data=pd.DataFrame()):
      global engine
      data.to_sql(name,engine,if_exists='fail',index=True)
  

  　　

调用上面封装方法：

# coding:utf-8
from mysql操作.write_SQL import write_sql
import os
import pandas as pd

path = r'your data path'

name_list = os.listdir(path)[0]

for item in [name_list]:
    name = item.split('.')[0]
    path_ = os.path.join(path,item)
    print(path_)
    with open(path_, 'rb') as f:
        data = pd.read_csv(f, sep=',', header=None, index_col=None, na_values=['NULL'], na_filter=True, encoding='utf8')
        write_sql(name,data)

print('打完收工！')