requests获取所有状态码
requests默认是不会获取301/302的状态码的。可以设置allow_redirects=False,这样就可以获取所有的状态码了
import requests # url # url = 'http://www.freebuf.com/news/157100.html' # 请求200,返回200 url = 'http://www.freebuf.com/fevents/133225.html' # 请求302,返回200。要想不跳转,获取302,用参数:allow_redirects=False # url = 'http://www.freebuf.com/articles/database/151839.html' # 请求403,返回403 # url = 'http://www.freebuf.com/articles/database/1518391.html' # 请求存在的域名中不存在的页面,请求404,返回404 # url = 'http://www.freebudfsf.com/articles/database/1518391.html' # 请求不存在的域名。程序崩溃 # url = 'https://www.douban.com/group/topic/49606658/' # 请求存在的域名,公司限制访问,返回抛出异常,程序崩溃。效果和网络中断一样。 # url = 'http://10.1.75.241' # 请求ip,(一定要加协议HTTP,否则崩溃) # headers headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36' } try: # 发请求,得响应 response = requests.get(url, headers=headers, allow_redirects=False) # 解析 print(' give url:', url) print(' request.url:', response.request.url) print('response.url:', response.url) print(response.content) print(response.status_code) except Exception as e: print(e)
封装一个获取所有状态码的函数,同时实现验证返回值的方法
import requests def get_statecode_or_errinfo(url=''): ''' 获取响应状态码,或者未响应的错误信息 :param url: 请求的url :return: 状态码,或者未响应的错误信息 ''' if url == '': return '请输入一个url作为get_statecode_or_errinfo的参数' # headers headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36' } try: # 发请求,得响应 response = requests.get(url, headers=headers, allow_redirects=False) # 返回状态码 return response.status_code except Exception as e: # 返回异常信息 return e if __name__ == '__main__': # url # url = 'http://www.freebuf.com/news/157100.html' # 请求200,返回200 url = 'http://www.freebuf.com/fevents/133225.html' # 请求302,返回200。要想不跳转,获取302,用参数:allow_redirects=False # url = 'http://www.freebuf.com/articles/database/151839.html' # 请求403,返回403 # url = 'http://www.freebuf.com/articles/database/1518391.html' # 请求存在的域名中不存在的页面,请求404,返回404 # url = 'http://www.freebudfsf.com/articles/database/1518391.html' # 请求不存在的域名。程序崩溃。如果有Nginx,返回200 # url = 'http://dsfs' # 请求不存在的域名,设置了参数:allow_redirects=False,在有Nginx处理的情况下,有304,返回200。 # url = 'https://www.douban.com/group/topic/49606658/' # 请求存在的域名,公司限制访问,返回抛出异常,程序崩溃。效果和网络中断一样。 # url = 'http://10.1.75.241' # 请求ip,请求200,返回200(一定要加协议HTTP,否则崩溃) # url = 'http://www.freebuf.com/fevents/133225.html' # 请求302,返回200。要想不跳转,获取302,用参数:allow_redirects=False url = 'http://www.freebuf.com/news/171238.html' headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36' } # response=requests.get(url,headers=headers,allow_redirects=False) response=requests.get(url,headers=headers) # 检查状态码 print(response.status_code) # # 检查url print(url) print(response.url) # # # 检查请求头 print(response.request.headers) # # # 检查响应头 print(response.headers) # # # 检查源码 # print(response.content) # print(response.content.decode()) # print(response.text) # # response.encoding = 'utf-8' # print(response.text) print(response.encoding) # # # 检查源码字符串长度 print(len(response.content))
说明:
反扒:
总结多种验证返回值的方式。requests
比如:检查状态码、检查url(有可能发送了跳转)、检查请求头、检查响应头、检查源码、检查源码字符串长度。
检查状态码
print (response.status_code)
检查url
print (response.url)
检查请求头
print (response.request.headers)
检查响应头
print (response.headers)
检查源码字符串长度
print (len(response.content))
检查源码
print (response.content)
print (response.content.decode())
response.encoding='utf-8'
print (response.text)
print (response.encoding)
scrapy爬虫的响应规则:
# 1、被过滤掉,不发出请求:不在允许的域名范围内 # temp['title_url'] = "https://www.baidu.com/" # 跨域。请求发出前,url直接被过滤掉。 # temp['title_url'] = "http://open.freebuf.com/live?id=1021" # 跨域。请求发出前,url直接被过滤掉。 # temp['title_url'] = "http://10.1.75.241" # 请求ip地址,请求发出前,url直接过来掉。如果设置为允许ip网站,没有被过滤,就返回200 # 2、禁止访问 # temp['title_url'] = "http://www.freebuf.com/articles/database/151839.html"#禁止访问403,资源存在,不让访问。Ignoring non-200 response # temp['title_url'] = "http://www.freebuf.com/articles/database/1518391.html"#禁止访问404,资源本身不存在。Ignoring non-200 response # 3、重定向后的作为新请求 # temp['title_url'] = "http://www.freebuf.com/news/156654.html" # 重定向301、302。会返回重定向后200的状态码 # 4、断网 # temp['title_url'] = "https://www.douban.com/group/topic/49606658/" # 公司限制访问。[<twisted.python.failure.Failure twisted.internet.error.ConnectionLost: Connection to the other side was lost in a non-clean fashion: Connection lost.>] # 5、没有的网站 # temp['title_url'] = "https://www.badfsdsdfsdfsdfsdddd.com/" # 直接被过滤掉,如果没有被过滤,就返回域名解析错误:DNS lookup failed: no results for hostname lookup: www.badfsdsdfsdfsdfsdddd.com. pass
scrapy爬虫举例
freebuf2.py
# -*- coding: utf-8 -*- import scrapy from scrapy_FB.items import ScrapyFb2Item # from util.logger import Logger # logger_freebuf2 = Logger(logname=__name__, logpath='collection_log', logformat=1, loglevel=10).getlog() # logger_freebuf2.debug('i am debug3') # logger_freebuf2.info('i am info3') # logger_freebuf2.warning('i am warning3') class Freebuf2Spider(scrapy.Spider): # freebuf2爬虫 name = 'freebuf2' allowed_domains = ['freebuf.com','douban.com'] start_urls = ['http://www.freebuf.com/page/708'] def parse(self, response): cur_url = response.url # 当前列表页url cur_page_num = int(cur_url.rpartition('/')[-1]) # 当前page num print('cur_url:%s' % cur_url) print('cur_page_num:%s' % cur_page_num) # 获取列表节点 node_list = response.xpath('//*[@id="timeline"]/div/div[2]/dl/dt/a[1]') print('len(node_list):%s' % len(node_list)) page_num = int(cur_url.rpartition('/')[-1]) # 当前页码 count_node = len(node_list) # 当前列表页,一共有的详细页条数 # 遍历节点 for i, node in enumerate(node_list): # temp = {} temp = ScrapyFb2Item() temp['title'] = node.xpath('./text()').extract()[0].strip() if i == 0: # 1、被过滤掉,不发出请求:不在允许的域名范围内 # temp['title_url'] = "https://www.baidu.com/" # 跨域。请求发出前,url直接被过滤掉。 # temp['title_url'] = "http://open.freebuf.com/live?id=1021" # 跨域。请求发出前,url直接被过滤掉。 # temp['title_url'] = "http://10.1.75.241" # 请求ip地址,请求发出前,url直接过来掉。如果设置为允许ip网站,没有被过滤,就返回200 # 2、禁止访问 # temp['title_url'] = "http://www.freebuf.com/articles/database/151839.html"#禁止访问403,资源存在,不让访问。Ignoring non-200 response # temp['title_url'] = "http://www.freebuf.com/articles/database/1518391.html"#禁止访问404,资源本身不存在。Ignoring non-200 response # 3、重定向后的作为新请求 # temp['title_url'] = "http://www.freebuf.com/news/156654.html" # 重定向301、302。会返回重定向后200的状态码 # 4、断网 # temp['title_url'] = "https://www.douban.com/group/topic/49606658/" # 公司限制访问。[<twisted.python.failure.Failure twisted.internet.error.ConnectionLost: Connection to the other side was lost in a non-clean fashion: Connection lost.>] # 5、没有的网站 # temp['title_url'] = "https://www.badfsdsdfsdfsdfsdddd.com/" # 直接被过滤掉,如果没有被过滤,就返回域名解析错误:DNS lookup failed: no results for hostname lookup: www.badfsdsdfsdfsdfsdddd.com. pass else: temp['title_url'] = node.xpath('./@href').extract()[0] temp['page_num'] = str(page_num) temp['line_num'] = i + 1 temp['line_total'] = str(count_node) # print(temp['line_num']) yield scrapy.Request(temp['title_url'], callback=self.parse_detail, meta={"meta_1": temp}, errback=self.err) if len(node_list) != 0: # 爬虫不终止的条件 # 下一页 next_url = 'http://www.freebuf.com/page/{}'.format(cur_page_num + 1) # print('next_url:%s' % next_url) yield scrapy.Request(next_url, callback=self.parse) # 访问下一页 def parse_detail(self, response): item = response.meta['meta_1'] print(item['line_num'], item['title_url']) # print(response.status) print(item['line_num'], response.request.url) def err(self, response): print('err:',response.request.url) # print('err:',response.status) # print(dir(response)) print('err:',response.getErrorMessage()) print(dir(response)) # print(type(response.getErrorMessage()))