【设置代理ip】
根据最新的scrapy官方文档,scrapy爬虫框架的代理配置有以下两种方法:
一.使用中间件DownloaderMiddleware进行配置
使用Scrapy默认方法scrapy startproject创建项目后项目目录结构如下,spider中的crawler是已经写好的爬虫程序:
settings.py文件其中的DOWNLOADER_MIDDLEWARES用于配置scrapy的中间件.我们可以在这里进行自己爬虫中间键的配置,配置后如下:
DOWNLOADER_MIDDLEWARES = {
'WandoujiaCrawler.middlewares.ProxyMiddleware': 100,
}
其中WandoujiaCrawler是我们的项目名称,后面的数字代表中间件执行的优先级,官方文档中默认proxy中间件的优先级编号是750,我们的中间件优先级要高于默认的proxy中间键.中间件middlewares.py的写法如下(scrapy默认会在这个文件中写好一个中间件的模板,不用管它写在后面即可):
# -*- coding: utf-8 -*-
class ProxyMiddleware(object):
def process_request(self, request, spider):
request.meta['proxy'] = "http://proxy.yourproxy:8001"
这里有两个问题:
一是proxy一定是要写号http://前缀的否则会出现to_bytes must receive a unicode, str or bytes object, got NoneType的错误.
二是官方文档中写到process_request方法一定要返回request对象,response对象或None的一种,但是其实写的时候不用return,乱写可能会报错.
另外如果代理有用户名密码等就需要在后面再加上一些内容:
# Use the following lines if your proxy requires authentication
proxy_user_pass = "USERNAME:PASSWORD"
# setup basic authentication for the proxy
encoded_user_pass = base64.encodestring(proxy_user_pass)
request.headers['Proxy-Authorization'] = 'Basic ' + encoded_user_pass
二.直接在爬虫程序中设置proxy字段
我们可以直接在自己具体的爬虫程序中设置proxy字段,代码如下,直接在构造Request里面加上meta字段即可:
class QuotesSpider(scrapy.Spider):
name = "quotes"
def start_requests(self):
urls = [
'http://quotes.toscrape.com/page/1/',
'http://quotes.toscrape.com/page/2/',
]
for url in urls:
yield scrapy.Request(url=url, callback=self.parse, meta={'proxy': 'http://proxy.yourproxy:8001'})
def parse(self, response):
for quote in response.css('div.quote'):
yield {
'text': quote.css('span.text::text').extract_first(),
'author': quote.css('span small::text').extract_first(),
'tags': quote.css('div.tags a.tag::text').extract(),
}
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第二种
1.在Scrapy工程下新建“middlewares.py”
1 # Importing base64 library because we'll need it ONLY in case if the proxy we are going to use requires authentication
2 import base64
3
4 # Start your middleware class
5 class ProxyMiddleware(object):
6 # overwrite process request
7 def process_request(self, request, spider):
8 # Set the location of the proxy
9 request.meta['proxy'] = "http://YOUR_PROXY_IP:PORT"
10
11 # Use the following lines if your proxy requires authentication
12 proxy_user_pass = "USERNAME:PASSWORD"
13 # setup basic authentication for the proxy
14 encoded_user_pass = base64.encodestring(proxy_user_pass)
15 request.headers['Proxy-Authorization'] = 'Basic ' + encoded_user_pass
16
17
18
2.在项目配置文件里(./project_name/settings.py)添加
1 DOWNLOADER_MIDDLEWARES = {
2 'scrapy.contrib.downloadermiddleware.httpproxy.HttpProxyMiddleware': 110,
3 'project_name.middlewares.ProxyMiddleware': 100,
4 }
只要两步,现在请求就是通过代理的了。测试一下^_^
1 from scrapy.spider import BaseSpider
2 from scrapy.contrib.spiders import CrawlSpider, Rule
3 from scrapy.http import Request
4
5 class TestSpider(CrawlSpider):
6 name = "test"
7 domain_name = "whatismyip.com"
8 # The following url is subject to change, you can get the last updated one from here :
9 # http://www.whatismyip.com/faq/automation.asp
10 start_urls = ["http://xujian.info"]
11
12 def parse(self, response):
13 open('test.html', 'wb').write(response.body)
14
增加文件middlewares.py放置在setting.py平行的目录下
1 import base64
2 class ProxyMiddleware(object):
3 # overwrite process request
4 def process_request(self, request, spider):
5 # Set the location of the proxy
6 request.meta['proxy'] = "http://YOUR_PROXY_IP:PORT"
7
8 # Use the following lines if your proxy requires authentication
9 proxy_user_pass = "USERNAME:PASSWORD"
10 # setup basic authentication for the proxy
11 encoded_user_pass = base64.b64encode(proxy_user_pass)
12 request.headers['Proxy-Authorization'] = 'Basic ' + encoded_user_pass
很多网上的答案使用base64.encodestring来编码proxy_user_pass,有一种情况,当username太长的时候,会出现错误,所以推荐使用b64encode编码方式
然后在setting.py中,在DOWNLOADER_MIDDLEWARES中把它打开,projectname.middlewares.ProxyMiddleware: 1就可以了
【设置headers和cookies】
scrapy中有三种方式设置headers,cookies
setting中设置cookie
middlewares中设置cookie
sipder文件中重写start_requests方法
这里记录第三种,重写start_requests方法,这里以豆瓣网为例
一、设置请求头headers
在start_request中新增
headers = {
'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36'
}
二、设置cookies
1、登录豆瓣网并获取cookie
首先在chrome中登录豆瓣网
按F12调出开发者工具
查看cookie
2、在start_requests中新增
cookies = {
'key':'value',
'key':'value',
'key':'value'
}
一行代码把字符串的cookies转字典
#bakooie装换成字典模式方便scrapy使用
cookid = "_ga=GA1.2.1937936278.1538889470; __gads=ID=1ba11c2610acf504:T=1539160131:S=ALNI_MZwhotFaAA6KsIVzHG-ev0RnU4OIQ; .CNBlogsCookie=7F3B19F5204038FAE6287F33828591011A60086D0F4349BEDA5F568571875F43E1EED5EDE24E458FAB8972604B4ECD19FC058F5562321A6D87ABF8AAC19F32EC6C004B2EBA69A29B8532E5464ECD145896AA49F1; .Cnblogs.AspNetCore.Cookies=CfDJ8J0rgDI0eRtJkfTEZKR_e81dD8ABr7voOOlhOqLJ7tzHG0h7wCeF8EYzLUZbtYueLnkUIzSWDE9LuJ-53nA6Lem4htKEIqdoOszI5xWb4PUZHJtM1qgEjI1E1Q8YLz8cU3jts5xoHMzq7qq7AmtrlCYYqvBMgEX8GACn8j61WrxZfKe9Hmh4akC9AxcODmAPP--axDI0w6LTSQYKl4GnKihmxM6DQ3RDCXXzWukG-3xiPfKv5vdSNFBTvj7b2qOeTmy45RWkQT9dqf_bXjniWnhPHRnGq8uNHqN2bpzUlCOxsrjwuZlhbAPPLCnX90XJaA; _gid=GA1.2.201165281.1540104585"
coolies = dict(i.split('=',1) for i in cookid.split(';'))
print(coolies)
3、修改方法返回值
yield scrapy.Request(url=url, headers=headers, cookies=cookies, callback=self.parse)
4、修改COOKIES_ENABLED
当COOKIES_ENABLED是注释的时候scrapy默认没有开启cookie
当COOKIES_ENABLED没有注释设置为False的时候scrapy默认使用了settings里面的cookie
当COOKIES_ENABLED设置为True的时候scrapy就会把settings的cookie关掉,使用自定义cookie
因此在settings.py文件中设置COOKIES_ENABLED = True
5、修改COOKIES_ENABLED
在settings.py文件中设置ROBOTSTXT_OBEY = False
三、测试
1、新建scrapy爬虫项目
scrapy stratproject douban
2、在./doouban/spiders/下新建short_spider.py文件
# -*- coding: utf-8 -*-
import scrapy
class ShortSpider(scrapy.Spider):
name = 'short'
allow_domains = ['movie.douban.com']
# 重写start_requests方法
def start_requests(self):
# 浏览器用户代理
headers = {
'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36'
}
# 指定cookies
cookies = {
'key':'value',
'key':'value',
'key':'value'
}
urls = [
'https://movie.douban.com/subject/26266893/comments?start=250&limit=20&sort=new_score&status=P'
]
for url in urls:
yield scrapy.Request(url=url, headers=headers, cookies=cookies, callback=self.parse)
def parse(self, response):
file_name = 'data.html'
with open(file_name, 'wb') as f:
f.write(response.body)
因为豆瓣电影短评论对未登录用户有限制,因此这里使用豆瓣电影段评论数比较靠后的页数进行测试
3、进入douban目录执行scrapy crawl short
状态码200,爬取成功(无权限返回403)