python连接MySQL，mongodb， redis的示例程序

系统管理员 2022-01-26 13:35 246阅读 0赞

# MySQL #

# -*- coding: utf-8 -*-
    
    # Define your item pipelines here
    #
    # Don't forget to add your pipeline to the ITEM_PIPELINES setting
    # See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html
    
    import pymysql
    
    
    class ConnectMysql(object):
        """ 存储数据 """
    
        def __init__(self):
            # 连接数据库
            self.connect = pymysql.connect(
                host='ip',
                db='dbname',
                user='root',
                passwd='pass',
                # charset='utf8',
                use_unicode=True)
    
            # 通过cursor执行增删查改
            self.cursor = self.connect.cursor()
    
    
        def _process_people(self, item):
            self.connect.ping(reconnect=True)
            
    
    
        def _process_relation(self, item):
            self.connect.ping(reconnect=True)
            
    
        def process_item(self, item, spider):
            """ 处理item """
            if isinstance(item, ZhihuPeopleItem):
                self._process_people(item)
            elif isinstance(item, ZhihuRelationItem):
                self._process_relation(item)
            return item

# mongodb #

import pymongo
    
    
    class TencentPipeline(object):
    
        def __init__(self):
            self.connection = pymongo.MongoClient('ip', port, connect=False)
            self.connection.admin.authenticate('name', 'pass')
            db = self.connection['taobao']
            db.authenticate('name', 'pass')
            self.collection1 = db['item']
    
        def process_item(self, item):
    
            item = dict(item)
            self.collection1.insert_one(item)

# redis #

#!/usr/bin/env python 
    # -*- coding: utf-8 -*- 
    # @Time : 2019/5/29 10:03 
    # @Author : zhao.jia
    # @Site : 
    # @File : read_redis.py 
    # @Software: PyCharm
    
    import redis
    
    ''' 这种连接是连接一次就断了，耗资源.端口默认6379，就不用写 r = redis.Redis(host='127.0.0.1',port=6379,password='tianxuroot') r.set('name','root') print(r.get('name').decode('utf8')) '''
    ''' 连接池： 当程序创建数据源实例时，系统会一次性创建多个数据库连接，并把这些数据库连接保存在连接池中，当程序需要进行数据库访问时， 无需重新新建数据库连接，而是从连接池中取出一个空闲的数据库连接 '''
    pool = redis.ConnectionPool(host='127.0.0.1',password='helloworld')   #实现一个连接池
    
    r = redis.Redis(connection_pool=pool)
    r.set('foo','bar')
    print(r.get('foo').decode('utf8'))