我有一个Scrapy中间件:
class ProxyMiddleware(object):
def __init__(self, settings):
self.proxy_file = settings.get('PROXY_FILE')
fin = open(self.proxy_file)
self.proxy_list = list()
for line in fin.readlines():
parts = line.strip().split()
proxy = parts[2] + '://' + parts[0] + ':' + parts[1]
self.proxy_list.append(proxy)
def process_request(self, request, spider):
request.meta['proxy'] = random.choice(self.proxy_list)
但是运行时出错了,设置是什么?
答案 0 :(得分:3)
如果您需要settings
对象来初始化中间件,则需要定义from_crawler()
类方法otherwise scrapy initializes the middleware without arguments。
查看内置中间件以获取灵感,例如HttpErrorMiddleware
class HttpErrorMiddleware(object):
@classmethod
def from_crawler(cls, crawler):
return cls(crawler.settings)
def __init__(self, settings):
self.handle_httpstatus_all = settings.getbool('HTTPERROR_ALLOW_ALL')
self.handle_httpstatus_list = settings.getlist('HTTPERROR_ALLOWED_CODES')
在你的情况下,它会是这样的:
class ProxyMiddleware(object):
@classmethod
def from_crawler(cls, crawler):
return cls(crawler.settings)
def __init__(self, settings):
self.proxy_file = settings.get('PROXY_FILE')
fin = open(self.proxy_file)
self.proxy_list = list()
for line in fin.readlines():
parts = line.strip().split()
proxy = parts[2] + '://' + parts[0] + ':' + parts[1]
self.proxy_list.append(proxy)
def process_request(self, request, spider):
request.meta['proxy'] = random.choice(self.proxy_list)