Scrapy+MongoDB爬虫实例教程_mongoclient scrapy

目录

一、MongoDB

1、下载、安装、配置环境变量、路径配置、启动

2、python操作MongoDB

二、Scrapy

1、安装、创建项目

2、修改、增加代码

①、编写 Spider 类

②、修改items.py

③、修改settings.py

④、修改pipelines.py

⑤、在tutorial下增加main.py

3、启动爬虫

4、成功

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本机环境：python3，Windows10

我的视频讲解：https://www.bilibili.com/video/BV1xh411C7Xc/

一、MongoDB

1、下载、安装、配置环境变量、路径配置、启动

2、python操作MongoDB

a. 安装pymongo

pip install pymongo

b. 基本操作

import pymongo
 
myclient = pymongo.MongoClient("mongodb://localhost:27017/")  #使用MongoClient对象，连接数据库
collist  = myclient.list_database_names()  # 获取所有数据库
mydb = myclient["runoobdb"]  # 数据库名
mycol = mydb["sites"]  # collection集合（类似SQL的表）
 
# 插入一条数据
mydict =  { "_id": 1, "name": "RUNOOB", "cn_name": "菜鸟教程"}
mycol.insert_one(mydict)
 
# 插入一组数据
mylist = [
  { "_id": 2, "name": "Google", "address": "Google 搜索"},
  { "_id": 3, "name": "Facebook", "address": "脸书"},
  { "_id": 4, "name": "Taobao", "address": "淘宝"},
  { "_id": 5, "name": "Zhihu", "address": "知乎"}
]
mycol.insert_many(mylist)
 
# 查找
for x in mycol.find({},{ "_id": 0, "name": 1, "alexa": 1 }):
  print(x)
 
# 删除全部
mycol.delete_many({})
print(list(mycol.find()))

二、Scrapy

1、安装、创建项目

scrapy startproject tutorial

2、修改、增加代码

①、编写 Spider 类

在tutorial/spiders目录下增加quotes_spider.py文件

import scrapy
from ..items import TutorialItem
 
class QuotesSpider(scrapy.Spider):
    name = "quotes"
    # 也可以如下
    # start_urls = ['http://quotes.toscrape.com/page/1/']
 
    def start_requests(self):
        url_bone = 'http://quotes.toscrape.com/page/{}/'
        for i in range(1,3):  # 要能够结束/有出口，否则为死循环
            url = url_bone.format(i)
            print('url: {}'.format(url))
            yield scrapy.Request(url=url, callback=self.parse)
 
    def parse(self, response):
        item = TutorialItem()
        div_list = response.xpath('/html/body/div/div[2]/div[1]/div')[:3]
        for div in div_list:
            words = div.xpath('./span[1]/text()').extract_first()
            person = div.xpath('./span[2]/small/text()').extract_first()
            item['words'] = words
            item['person'] = person
            yield item

通过xpath来定位：

a、F12 检查， 找到对应位置，右键copy-copy xpath

b、使用chrome插件 xpath helper

 

②、修改items.py

class TutorialItem(scrapy.Item):
    # define the fields for your item here like:
    words = scrapy.Field()  # 一个人说的话
    person = scrapy.Field()  # 说话的人

③、修改settings.py

ROBOTSTXT_OBEY = False  #修改为False
LOG_LEVEL = 'ERROR'  #只有在错误时才打印日志
DOWNLOAD_DELAY = 1  # 下载时间间隔改为1秒
# 配置默认的请求头
DEFAULT_REQUEST_HEADERS = {
    "User-Agent" : "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0",
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'
}
# 配置使用Pipeline
ITEM_PIPELINES = {
   'tutorial.pipelines.TutorialPipeline': 300,
}

④、修改pipelines.py

import pymongo
 
class TutorialPipeline(object):
    def __init__(self):
        super().__init__()
        myclient = pymongo.MongoClient("mongodb://localhost:27017/")
        mydb = myclient["runoobdb"]
        self.mycol = mydb["quotes"]
 
    def process_item(self, item, spider):
        print(item)
        self.mycol.insert_one(dict(item))
        return item

⑤、在tutorial下增加main.py

from scrapy import cmdline
 
cmdline.execute('scrapy crawl quotes'.split())

3、启动爬虫

cd到main.py的位置 xx/tutorial/tutorial

python main.py

4、成功

参考资料：

scrapy官方手册中文版

MongoDB文档

https://blog.csdn.net/qq_41837900/article/details/96489994

待爬网址：http://quotes.toscrape.com/page/1/

 

本项目代码位置：https://download.csdn.net/download/GreatXiang888/15108875