上下文管理器

#!/usr/bin/python3
# coding:utf8

import pymysql

class Database():

    def __init__(self):
        self.conn = pymysql.Connect(
            host='127.0.0.1',
            port=3306,
            user='root',  #使用自己的用户名
            passwd='123',  # 使用自己的密码
            db='马继',  # 数据库名
            charset='utf8'
        )

    def __enter__(self,):
        return self.conn.cursor(cursor=DictCursor)

    def __exit__(self, exc_type, exc_val, exc_tb):
        if exc_type:
            self.conn.rollback()
        else:
            self.conn.commit()
        return True
    def close(self):
        self.conn.close()

# 数据库存储

class Base():
    def __init__(self):
        self.db = Database()

    def save(self,table_name,**item):
        sql = 'insert into %s(%s) values(%s)'
        fields = ''.join(item.keys())
        fields_placeholds = ''.join(['%%(%s)s' % key for key in item])
        with self.db as cursor:
            cursor.execute(sql % (table_name,fields,fields_placeholds),
                           item)
            # 判断是否执行成功
            # rowcount影响的行数
            if cursor.rowcount>0:
                return True
        return False