how to handle 302 redirect in scrapy
I am receiving a 302 response from a server while scrapping a website:
2014-04-01 21:31:51+0200 [ahrefs-h] DEBUG: Redirecting (302) to <GET http://www.domain.com/Site_Abuse/DeadEnd.htm> from <GET http://domain.com/wps/showmodel.asp?Type=15&make=damc&a=664&b=51&c=0>
I want to send request to GET urls instead of being redirected. Now I found this middleware:
https://github.com/scrapy/scrapy/blob/master/scrapy/contrib/downloadermiddleware/redirect.py#L31
I added this redirect code to my middleware.py file and I added this into settings.py:
DOWNLOADER_MIDDLEWARES = {
'street.middlewares.RandomUserAgentMiddleware': 400,
'street.middlewares.RedirectMiddleware': 100,
'scrapy.contrib.downloadermiddleware.useragent.UserAgentMiddleware': None,
}
But I am still getting redirected. Is that all I have to do in order to get this middleware working? Do I miss something?
Forgot about middlewares in this scenario, this will do the trick:
meta = {'dont_redirect': True,'handle_httpstatus_list': [302]}
That said, you will need to include meta parameter when you yield your request:
yield Request(item['link'],meta = {
'dont_redirect': True,
'handle_httpstatus_list': [302]
}, callback=self.your_callback)
An unexplicable 302
response, such as redirecting from a page that loads fine in a web browser to the home page or some fixed page, usually indicates a server-side measure against undesired activity.
You must either reduce your crawl rate or use a smart proxy (e.g. Crawlera) or a proxy-rotation service and retry your requests when you get such a response.
To retry such a response, add 'handle_httpstatus_list': [302]
to the meta
of the source request, and check if response.status == 302
in the callback. If it is, retry your request by yielding response.request.replace(dont_filter=True)
.
When retrying, you should also make your code limit the maximum number of retries of any given URL. You could keep a dictionary to track retries:
class MySpider(Spider):
name = 'my_spider'
max_retries = 2
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.retries = {}
def start_requests(self):
yield Request(
'https://example.com',
callback=self.parse,
meta={
'handle_httpstatus_list': [302],
},
)
def parse(self, response):
if response.status == 302:
retries = self.retries.setdefault(response.url, 0)
if retries < self.max_retries:
self.retries[response.url] += 1
yield response.request.replace(dont_filter=True)
else:
self.logger.error('%s still returns 302 responses after %s retries',
response.url, retries)
return
Depending on the scenario, you might want to move this code to a downloader middleware.
You can disable the RedirectMiddleware by setting REDIRECT_ENABLED
to False in settings.py