使用scrapy 把爬到的数据保存到mysql 防止重复

1.环境建立

1.使用xmapp安装php, mysql ,phpmyadmin

2.安装python3，pip

3.安装pymysql

3.(windows 略)我这边是mac，安装brew，用brew 安装scrapy

2.整个流程

1. 创建数据库和数据库表，准备保存

2.写入爬虫目标URL，进行网络请求

3.对爬返回数据进行处理，得到具体数据

4.对于具体数据保存到数据库中

2.1.创建数据库

首先创建一个数据库叫scrapy，然后创建一个表article，我们这里给body加了唯一索引，防止重复插入数据

--
-- Database: `scrapy`
--

-- --------------------------------------------------------

--
-- 表的结构 `article`
--

CREATE TABLE `article` (
  `id` int(11) NOT NULL,
  `body` varchar(200) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `author` varchar(50) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `createDate` datetime NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;


--
-- Indexes for table `article`
--
ALTER TABLE `article`
  ADD PRIMARY KEY (`id`),
  ADD UNIQUE KEY `uk_body` (`body`);

弄好以后是这样的。

2.2 先看下整个爬虫项目的结构

quotes_spider.py是核心，负责对网络请求和对内容进行处理，然后对整理好的内容抛给pipelines进行具体处理，保存到数据库中，这样不会影响速度。

其他的看 图说明

2.2 写入爬虫目标URL，进行网络请求

import scrapy

from tutorial.items import TutorialItem

class QuotesSpider(scrapy.Spider):
    name = "quotes"

    def start_requests(self):
        url = 'http://quotes.toscrape.com/tag/humor/'
        yield scrapy.Request(url)

    def parse(self, response):
        item = TutorialItem()
        for quote in response.css('div.quote'):
            item['body'] = quote.css('span.text::text').extract_first()
            item['author'] = quote.css('small.author::text').extract_first()
            yield item
        next_page = response.css('li.next a::attr("href")').extract_first()
        if next_page is not None:
            yield response.follow(next_page, self.parse)

start_requests 就是要写入具体要爬的URL

parse就是核心的对返回的数据进行处理的地方，然后以item的形式抛出，接下来定义好下一个要爬的内容

2.3  items

# -*- coding: utf-8 -*-

# Define here the models for your scraped items
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/items.html

import scrapy


class TutorialItem(scrapy.Item):
    body = scrapy.Field()
    author = scrapy.Field()
    pass

2.4 pipelines

# -*- 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
import datetime
from tutorial import settings
import logging

class TutorialPipeline(object):
    def __init__(self):
        self.connect = pymysql.connect(
            host = settings.MYSQL_HOST,
            db = settings.MYSQL_DBNAME,
            user = settings.MYSQL_USER,
            passwd = settings.MYSQL_PASSWD,
            charset = 'utf8',
            use_unicode = True
        )
        self.cursor = self.connect.cursor();

    def process_item(self, item, spider):
        try:
            self.cursor.execute(
                "insert into article (body, author, createDate) value(%s, %s, %s) on duplicate key update author=(author)",
                (item['body'],
                 item['author'],
                 datetime.datetime.now()
                 ))
            self.connect.commit()
        except Exception as error:
            logging.log(error)
        return item

    def close_spider(self, spider):
        self.connect.close();

2.5 配置

ITEM_PIPELINES = {
    'tutorial.pipelines.TutorialPipeline':300
}

MYSQL_HOST = 'localhost'
MYSQL_DBNAME = 'scrapy'
MYSQL_USER = 'root'
MYSQL_PASSWD = '123456'
MYSQL_PORT = 3306

3.启动爬虫

scrapy crawl quotes

http://www.waitingfy.com/archives/1989

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