Scrapy框架的使用方法

一、安装 scrapy

pip install scrapy

 

二、创建项目

scrapy startproject myproject

 

三、生成爬虫类

cd myproject
scrapy genspider baidu baidu.com

 

四、创建数据对象

修改 items.py，增加以下内容

 

五、编写爬虫脚本

修改第三步生成的 baidu.py，编写处理响应数据的代码

import scrapy
from myproject.items import MyprojectItem


class BaiduSpider(scrapy.Spider):
    name = 'baidu'
    allowed_domains = ['baidu.com']
    start_urls = ['http://baidu.com/']

    def parse(self, response):
        hotsearch = response.css('.hotsearch-item')
        for li in hotsearch:
            item = MyprojectItem()
            item['name'] = li.css('.title-content-title::text').get()
            item['link'] = li.css('a::attr(href)').get()
            yield item

 

六、禁用 robots 规则

 

七、运行爬虫

scrapy crawl baidu -o hotsearch.csv

 

八、新建命令脚本

from scrapy import cmdline

cmdline.execute('scrapy crawl baidu -o hotsearch.csv'.split())

注：现在就可以直接使用 python baidu.py 来启动爬虫，免去手动传参

 

九、集成 Selenium 中间件

import time
import requests
from pathlib import Path
from selenium import webdriver
from scrapy.http.response.html import HtmlResponse


class SeleniumMiddlewares(object):

    def __init__(self):
        print('初始化浏览器')
        _driver = Path('./../drivers/chromedriver.exe')

        if _driver.exists() is False:
            print('异常：未找到浏览器驱动')
            print('提示：请下载对应版本的浏览器驱动，并放置于 %s/ 目录中' % str(_driver.parent))
            print('chrome: https://chromedriver.storage.googleapis.com/index.html')
            return

        options = webdriver.ChromeOptions()
        options.add_argument('log-level=3')
        options.add_argument('--disable-blink-features')
        options.add_argument('--disable-blink-features=AutomationControlled')
        options.add_experimental_option('excludeSwitches', ['enable-logging', 'enable-automation'])
        options.add_experimental_option('useAutomationExtension', False)
        # proxy_url = requests.get('http://webapi.http.zhimacangku.com/getip?num=1&type=1&pro=&city=0&yys=0&port=1&pack=99172&ts=0&ys=0&cs=0&lb=1&sb=0&pb=4&mr=1&regions=').text
        # print(proxy_url)
        # options.add_argument('--proxy-server=%s' % proxy_url)  # 添加代理
        self.driver = webdriver.Chrome(options=options, executable_path=str(_driver))
        self.driver.maximize_window()

    def process_request(self, request, spider):
        self.driver.get(request.url)
        time.sleep(5)
        # 我们等待5秒钟，让其加载
        source = self.driver.page_source
        # 获取页面的源码
        # Response 对象用来描述一个HTTP响应
        response = HtmlResponse(url=self.driver.current_url, body=source, request=request, encoding='utf-8')
        return response

 

十、官方文档

Command line tool — Scrapy 2.6.1 documentation

Items — Scrapy 2.6.1 documentation

Selectors — Scrapy 2.6.1 documentation

Item Pipeline — Scrapy 2.6.1 documentation

Downloader Middleware — Scrapy 2.6.1 documentation