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# Define here the models for your spider middleware | |
# | |
# See documentation in: | |
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html | |
# useful for handling different item types with a single interface | |
from itemadapter import ItemAdapter, is_item | |
from scrapy import signals | |
class TutorialSpiderMiddleware: | |
# Not all methods need to be defined. If a method is not defined, | |
# scrapy acts as if the spider middleware does not modify the | |
# passed objects. | |
def from_crawler(cls, crawler): | |
# This method is used by Scrapy to create your spiders. | |
s = cls() | |
crawler.signals.connect(s.spider_opened, signal=signals.spider_opened) | |
return s | |
def process_spider_input(self, response, spider): | |
# Called for each response that goes through the spider | |
# middleware and into the spider. | |
# Should return None or raise an exception. | |
return None | |
def process_spider_output(self, response, result, spider): | |
# Called with the results returned from the Spider, after | |
# it has processed the response. | |
# Must return an iterable of Request, or item objects. | |
for i in result: | |
yield i | |
def process_spider_exception(self, response, exception, spider): | |
# Called when a spider or process_spider_input() method | |
# (from other spider middleware) raises an exception. | |
# Should return either None or an iterable of Request or item objects. | |
pass | |
def process_start_requests(self, start_requests, spider): | |
# Called with the start requests of the spider, and works | |
# similarly to the process_spider_output() method, except | |
# that it doesn’t have a response associated. | |
# Must return only requests (not items). | |
for r in start_requests: | |
yield r | |
def spider_opened(self, spider): | |
spider.logger.info("Spider opened: %s" % spider.name) | |
class TutorialDownloaderMiddleware: | |
# Not all methods need to be defined. If a method is not defined, | |
# scrapy acts as if the downloader middleware does not modify the | |
# passed objects. | |
def from_crawler(cls, crawler): | |
# This method is used by Scrapy to create your spiders. | |
s = cls() | |
crawler.signals.connect(s.spider_opened, signal=signals.spider_opened) | |
return s | |
def process_request(self, request, spider): | |
# Called for each request that goes through the downloader | |
# middleware. | |
# Must either: | |
# - return None: continue processing this request | |
# - or return a Response object | |
# - or return a Request object | |
# - or raise IgnoreRequest: process_exception() methods of | |
# installed downloader middleware will be called | |
return None | |
def process_response(self, request, response, spider): | |
# Called with the response returned from the downloader. | |
# Must either; | |
# - return a Response object | |
# - return a Request object | |
# - or raise IgnoreRequest | |
return response | |
def process_exception(self, request, exception, spider): | |
# Called when a download handler or a process_request() | |
# (from other downloader middleware) raises an exception. | |
# Must either: | |
# - return None: continue processing this exception | |
# - return a Response object: stops process_exception() chain | |
# - return a Request object: stops process_exception() chain | |
pass | |
def spider_opened(self, spider): | |
spider.logger.info("Spider opened: %s" % spider.name) | |