Scrapy使用详细记录

import scrapyclass Product(scrapy.Item):
name = scrapy.Field()
price = scrapy.Field()
stock = scrapy.Field()
last_updated = scrapy.Field(serializer=str)

USER_AGENTS = [
"Mozilla/5.0 (Linux; U; Android 2.3.6; en-us; Nexus S Build/GRK39F) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Avant Browser/1.2.789rel1 (http://www.avantbrowser.com)",
"Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.0.249.0 Safari/532.5",
"Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US) AppleWebKit/532.9 (KHTML, like Gecko) Chrome/5.0.310.0 Safari/532.9",
"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/534.7 (KHTML, like Gecko) Chrome/7.0.514.0 Safari/534.7",
"Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/534.14 (KHTML, like Gecko) Chrome/9.0.601.0 Safari/534.14",
"Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.14 (KHTML, like Gecko) Chrome/10.0.601.0 Safari/534.14",
"Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.20 (KHTML, like Gecko) Chrome/11.0.672.2 Safari/534.20",
"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.27 (KHTML, like Gecko) Chrome/12.0.712.0 Safari/534.27",
"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.24 Safari/535.1",
"Mozilla/5.0 (Windows NT 6.0) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.120 Safari/535.2",
"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.36 Safari/535.7",
"Mozilla/5.0 (Windows; U; Windows NT 6.0 x64; en-US; rv:1.9pre) Gecko/2008072421 Minefield/3.0.2pre",
"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.10) Gecko/2009042316 Firefox/3.0.10",
"Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.9.0.11) Gecko/2009060215 Firefox/3.0.11 (.NET CLR 3.5.30729)",
"Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.6) Gecko/20091201 Firefox/3.5.6 GTB5",
"Mozilla/5.0 (Windows; U; Windows NT 5.1; tr; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 ( .NET CLR 3.5.30729; .NET4.0E)",
"Mozilla/5.0 (Windows NT 6.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1",
"Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:2.0.1) Gecko/20100101 Firefox/4.0.1",
"Mozilla/5.0 (Windows NT 5.1; rv:5.0) Gecko/20100101 Firefox/5.0",
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0a2) Gecko/20110622 Firefox/6.0a2",
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1",
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b4pre) Gecko/20100815 Minefield/4.0b4pre",
"Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0 )",
"Mozilla/4.0 (compatible; MSIE 5.5; Windows 98; Win 9x 4.90)",
"Mozilla/5.0 (Windows; U; Windows XP) Gecko MultiZilla/1.6.1.0a",
"Mozilla/2.02E (Win95; U)",
"Mozilla/3.01Gold (Win95; I)",
"Mozilla/4.8 [en] (Windows NT 5.1; U)",
"Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.4) Gecko Netscape/7.1 (ax)",
"HTC_Dream Mozilla/5.0 (Linux; U; Android 1.5; en-ca; Build/CUPCAKE) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
"Mozilla/5.0 (hp-tablet; Linux; hpwOS/3.0.2; U; de-DE) AppleWebKit/534.6 (KHTML, like Gecko) wOSBrowser/234.40.1 Safari/534.6 TouchPad/1.0",
"Mozilla/5.0 (Linux; U; Android 1.5; en-us; sdk Build/CUPCAKE) AppleWebkit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
"Mozilla/5.0 (Linux; U; Android 2.1; en-us; Nexus One Build/ERD62) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 2.2; en-us; Nexus One Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Mozilla/5.0 (Linux; U; Android 1.5; en-us; htc_bahamas Build/CRB17) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
"Mozilla/5.0 (Linux; U; Android 2.1-update1; de-de; HTC Desire 1.19.161.5 Build/ERE27) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Mozilla/5.0 (Linux; U; Android 1.5; de-ch; HTC Hero Build/CUPCAKE) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
"Mozilla/5.0 (Linux; U; Android 2.2; en-us; ADR6300 Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Mozilla/5.0 (Linux; U; Android 2.1; en-us; HTC Legend Build/cupcake) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 1.5; de-de; HTC Magic Build/PLAT-RC33) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1 FirePHP/0.3",
"Mozilla/5.0 (Linux; U; Android 1.6; en-us; HTC_TATTOO_A3288 Build/DRC79) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
"Mozilla/5.0 (Linux; U; Android 1.0; en-us; dream) AppleWebKit/525.10 (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
"Mozilla/5.0 (Linux; U; Android 1.5; en-us; T-Mobile G1 Build/CRB43) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari 525.20.1",
"Mozilla/5.0 (Linux; U; Android 1.5; en-gb; T-Mobile_G2_Touch Build/CUPCAKE) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
"Mozilla/5.0 (Linux; U; Android 2.0; en-us; Droid Build/ESD20) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 2.2; en-us; Droid Build/FRG22D) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Mozilla/5.0 (Linux; U; Android 2.0; en-us; Milestone Build/ SHOLS_U2_01.03.1) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 2.0.1; de-de; Milestone Build/SHOLS_U2_01.14.0) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 3.0; en-us; Xoom Build/HRI39) AppleWebKit/525.10 (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
"Mozilla/5.0 (Linux; U; Android 0.5; en-us) AppleWebKit/522 (KHTML, like Gecko) Safari/419.3",
"Mozilla/5.0 (Linux; U; Android 1.1; en-gb; dream) AppleWebKit/525.10 (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
"Mozilla/5.0 (Linux; U; Android 2.0; en-us; Droid Build/ESD20) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 2.1; en-us; Nexus One Build/ERD62) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
"Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Mozilla/5.0 (Linux; U; Android 2.2; en-us; ADR6300 Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Mozilla/5.0 (Linux; U; Android 2.2; en-ca; GT-P1000M Build/FROYO) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
"Mozilla/5.0 (Linux; U; Android 3.0.1; fr-fr; A500 Build/HRI66) AppleWebKit/534.13 (KHTML, like Gecko) Version/4.0 Safari/534.13",
"Mozilla/5.0 (Linux; U; Android 3.0; en-us; Xoom Build/HRI39) AppleWebKit/525.10 (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
"Mozilla/5.0 (Linux; U; Android 1.6; es-es; SonyEricssonX10i Build/R1FA016) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
"Mozilla/5.0 (Linux; U; Android 1.6; en-us; SonyEricssonX10i Build/R1AA056) AppleWebKit/528.5 (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
]

# 随机User-Agent
class RandomUserAgentMiddleware(object):
def __init__(self, agents):
"""接收从from_crawler传的List-agents"""
self.agents = agents @classmethod
def from_crawler(cls, crawler):
"""从settings读取USER_AGENTS，传参到构造函数"""
return cls(crawler.settings.getlist('USER_AGENTS')) def process_request(self, request, spider):
"""修改每一个request的header"""
request.headers.setdefault('User-Agent', random.choice(self.agents))

DOWNLOADER_MIDDLEWARES = {
'tutorial.middlewares.RandomUserAgentMiddleware': 1
}

# 代理服务器
class ProxyMiddleware(object): def process_request(self, request, spider):
"""设置代理"""
request.meta['proxy'] = 'http://115.226.140.24:44978'

DOWNLOADER_MIDDLEWARES = {
'tutorial.middlewares.RandomUserAgentMiddleware': 1,
'tutorial.middlewares.ProxyMiddleware': 556
}

# Cookies更新
class CookiesMiddleware(object): def get_cookies(self):
# 1.从redis中获取
# 2.http接口
pass def process_request(self, request, spider):
request.cookies = self.get_cookies()

class WenshuPipeline(object): def process_item(self, item, spider):
date = item['date']
# 一个日期一个文件
with open(date + '.txt', 'a', encoding='utf-8') as f:
f.write(item['json_data'] + "\n")

ITEM_PIPELINES = {
'tutorial.pipelines.WenshuPipeline': 300,
}

class Request(object_ref): def __init__(self, url, callback=None, method='GET', headers=None, body=None,
cookies=None, meta=None, encoding='utf-8', priority=0,
dont_filter=False, errback=None, flags=None): self._encoding = encoding # this one has to be set first
self.method = str(method).upper()
self._set_url(url)
self._set_body(body)
assert isinstance(priority, int), "Request priority not an integer: %r" % priority
self.priority = priority if callback is not None and not callable(callback):
raise TypeError('callback must be a callable, got %s' % type(callback).__name__)
if errback is not None and not callable(errback):
raise TypeError('errback must be a callable, got %s' % type(errback).__name__)
assert callback or not errback, "Cannot use errback without a callback"
self.callback = callback
self.errback = errback self.cookies = cookies or {}
self.headers = Headers(headers or {}, encoding=encoding)
self.dont_filter = dont_filter self._meta = dict(meta) if meta else None
self.flags = [] if flags is None else list(flags) @property
def meta(self):
if self._meta is None:
self._meta = {}
return self._meta def _get_url(self):
return self._url def _set_url(self, url):
if not isinstance(url, six.string_types):
raise TypeError('Request url must be str or unicode, got %s:' % type(url).__name__) s = safe_url_string(url, self.encoding)
self._url = escape_ajax(s) if ':' not in self._url:
raise ValueError('Missing scheme in request url: %s' % self._url) url = property(_get_url, obsolete_setter(_set_url, 'url')) def _get_body(self):
return self._body def _set_body(self, body):
if body is None:
self._body = b''
else:
self._body = to_bytes(body, self.encoding) body = property(_get_body, obsolete_setter(_set_body, 'body')) @property
def encoding(self):
return self._encoding def __str__(self):
return "<%s %s>" % (self.method, self.url) __repr__ = __str__ def copy(self):
"""Return a copy of this Request"""
return self.replace() def replace(self, *args, **kwargs):
"""Create a new Request with the same attributes except for those
given new values.
"""
for x in ['url', 'method', 'headers', 'body', 'cookies', 'meta',
'encoding', 'priority', 'dont_filter', 'callback', 'errback']:
kwargs.setdefault(x, getattr(self, x))
cls = kwargs.pop('cls', self.__class__)
return cls(*args, **kwargs)

class FormRequest(Request): def __init__(self, *args, **kwargs):
formdata = kwargs.pop('formdata', None)
if formdata and kwargs.get('method') is None:
kwargs['method'] = 'POST' super(FormRequest, self).__init__(*args, **kwargs) if formdata:
items = formdata.items() if isinstance(formdata, dict) else formdata
querystr = _urlencode(items, self.encoding)
if self.method == 'POST':
self.headers.setdefault(b'Content-Type', b'application/x-www-form-urlencoded')
self._set_body(querystr)
else:
self._set_url(self.url + ('&' if '?' in self.url else '?') + querystr) @classmethod
def from_response(cls, response, formname=None, formid=None, formnumber=0, formdata=None,
clickdata=None, dont_click=False, formxpath=None, formcss=None, **kwargs): kwargs.setdefault('encoding', response.encoding) if formcss is not None:
from parsel.csstranslator import HTMLTranslator
formxpath = HTMLTranslator().css_to_xpath(formcss) form = _get_form(response, formname, formid, formnumber, formxpath)
formdata = _get_inputs(form, formdata, dont_click, clickdata, response)
url = _get_form_url(form, kwargs.pop('url', None))
method = kwargs.pop('method', form.method)
return cls(url=url, method=method, formdata=formdata, **kwargs)def _get_form_url(form, url):
if url is None:
action = form.get('action')
if action is None:
return form.base_url
return urljoin(form.base_url, strip_html5_whitespace(action))
return urljoin(form.base_url, url)def _urlencode(seq, enc):
values = [(to_bytes(k, enc), to_bytes(v, enc))
for k, vs in seq
for v in (vs if is_listlike(vs) else [vs])]
return urlencode(values, doseq=1)def _get_form(response, formname, formid, formnumber, formxpath):
"""Find the form element """
root = create_root_node(response.text, lxml.html.HTMLParser,
base_url=get_base_url(response))
forms = root.xpath('//form')
if not forms:
raise ValueError("No <form> element found in %s" % response) if formname is not None:
f = root.xpath('//form[@name="%s"]' % formname)
if f:
return f[0] if formid is not None:
f = root.xpath('//form[@id="%s"]' % formid)
if f:
return f[0] # Get form element from xpath, if not found, go up
if formxpath is not None:
nodes = root.xpath(formxpath)
if nodes:
el = nodes[0]
while True:
if el.tag == 'form':
return el
el = el.getparent()
if el is None:
break
encoded = formxpath if six.PY3 else formxpath.encode('unicode_escape')
raise ValueError('No <form> element found with %s' % encoded) # If we get here, it means that either formname was None
# or invalid
if formnumber is not None:
try:
form = forms[formnumber]
except IndexError:
raise IndexError("Form number %d not found in %s" %
(formnumber, response))
else:
return formdef _get_inputs(form, formdata, dont_click, clickdata, response):
try:
formdata = dict(formdata or ())
except (ValueError, TypeError):
raise ValueError('formdata should be a dict or iterable of tuples') inputs = form.xpath('descendant::textarea'
'|descendant::select'
'|descendant::input[not(@type) or @type['
' not(re:test(., "^(?:submit|image|reset)$", "i"))'
' and (../@checked or'
' not(re:test(., "^(?:checkbox|radio)$", "i")))]]',
namespaces={
"re": "http://exslt.org/regular-expressions"})
values = [(k, u'' if v is None else v)
for k, v in (_value(e) for e in inputs)
if k and k not in formdata] if not dont_click:
clickable = _get_clickable(clickdata, form)
if clickable and clickable[0] not in formdata and not clickable[0] is None:
values.append(clickable) values.extend((k, v) for k, v in formdata.items() if v is not None)
return valuesdef _value(ele):
n = ele.name
v = ele.value
if ele.tag == 'select':
return _select_value(ele, n, v)
return n, vdef _select_value(ele, n, v):
multiple = ele.multiple
if v is None and not multiple:
# Match browser behaviour on simple select tag without options selected
# And for select tags wihout options
o = ele.value_options
return (n, o[0]) if o else (None, None)
elif v is not None and multiple:
# This is a workround to bug in lxml fixed 2.3.1
# fix https://github.com/lxml/lxml/commit/57f49eed82068a20da3db8f1b18ae00c1bab8b12#L1L1139
selected_options = ele.xpath('.//option[@selected]')
v = [(o.get('value') or o.text or u'').strip() for o in selected_options]
return n, vdef _get_clickable(clickdata, form):
"""
Returns the clickable element specified in clickdata,
if the latter is given. If not, it returns the first
clickable element found
"""
clickables = [
el for el in form.xpath(
'descendant::*[(self::input or self::button)'
' and re:test(@type, "^submit$", "i")]'
'|descendant::button[not(@type)]',
namespaces={"re": "http://exslt.org/regular-expressions"})
]
if not clickables:
return # If we don't have clickdata, we just use the first clickable element
if clickdata is None:
el = clickables[0]
return (el.get('name'), el.get('value') or '') # If clickdata is given, we compare it to the clickable elements to find a
# match. We first look to see if the number is specified in clickdata,
# because that uniquely identifies the element
nr = clickdata.get('nr', None)
if nr is not None:
try:
el = list(form.inputs)[nr]
except IndexError:
pass
else:
return (el.get('name'), el.get('value') or '') # We didn't find it, so now we build an XPath expression out of the other
# arguments, because they can be used as such
xpath = u'.//*' + \
u''.join(u'[@%s="%s"]' % c for c in six.iteritems(clickdata))
el = form.xpath(xpath)
if len(el) == 1:
return (el[0].get('name'), el[0].get('value') or '')
elif len(el) > 1:
raise ValueError("Multiple elements found (%r) matching the criteria "
"in clickdata: %r" % (el, clickdata))
else:
raise ValueError('No clickable element matching clickdata: %r' % (clickdata,))

"""
This module implements the Response class which is used to represent HTTP
responses in Scrapy.See documentation in docs/topics/request-response.rst
"""
from six.moves.urllib.parse import urljoinfrom scrapy.http.request import Request
from scrapy.http.headers import Headers
from scrapy.link import Link
from scrapy.utils.trackref import object_ref
from scrapy.http.common import obsolete_setter
from scrapy.exceptions import NotSupportedclass Response(object_ref): def __init__(self, url, status=200, headers=None, body=b'', flags=None, request=None):
self.headers = Headers(headers or {})
self.status = int(status)
self._set_body(body)
self._set_url(url)
self.request = request
self.flags = [] if flags is None else list(flags) @property
def meta(self):
try:
return self.request.meta
except AttributeError:
raise AttributeError(
"Response.meta not available, this response "
"is not tied to any request"
) def _get_url(self):
return self._url def _set_url(self, url):
if isinstance(url, str):
self._url = url
else:
raise TypeError('%s url must be str, got %s:' % (type(self).__name__,
type(url).__name__)) url = property(_get_url, obsolete_setter(_set_url, 'url')) def _get_body(self):
return self._body def _set_body(self, body):
if body is None:
self._body = b''
elif not isinstance(body, bytes):
raise TypeError(
"Response body must be bytes. "
"If you want to pass unicode body use TextResponse "
"or HtmlResponse.")
else:
self._body = body body = property(_get_body, obsolete_setter(_set_body, 'body')) def __str__(self):
return "<%d %s>" % (self.status, self.url) __repr__ = __str__ def copy(self):
"""Return a copy of this Response"""
return self.replace() def replace(self, *args, **kwargs):
"""Create a new Response with the same attributes except for those
given new values.
"""
for x in ['url', 'status', 'headers', 'body', 'request', 'flags']:
kwargs.setdefault(x, getattr(self, x))
cls = kwargs.pop('cls', self.__class__)
return cls(*args, **kwargs) def urljoin(self, url):
"""Join this Response's url with a possible relative url to form an
absolute interpretation of the latter."""
return urljoin(self.url, url) @property
def text(self):
"""For subclasses of TextResponse, this will return the body
as text (unicode object in Python 2 and str in Python 3)
"""
raise AttributeError("Response content isn't text") def css(self, *a, **kw):
"""Shortcut method implemented only by responses whose content
is text (subclasses of TextResponse).
"""
raise NotSupported("Response content isn't text") def xpath(self, *a, **kw):
"""Shortcut method implemented only by responses whose content
is text (subclasses of TextResponse).
"""
raise NotSupported("Response content isn't text") def follow(self, url, callback=None, method='GET', headers=None, body=None,
cookies=None, meta=None, encoding='utf-8', priority=0,
dont_filter=False, errback=None):
# type: (...) -> Request
"""
Return a :class:`~.Request` instance to follow a link ``url``.
It accepts the same arguments as ``Request.__init__`` method,
but ``url`` can be a relative URL or a ``scrapy.link.Link`` object,
not only an absolute URL. :class:`~.TextResponse` provides a :meth:`~.TextResponse.follow`
method which supports selectors in addition to absolute/relative URLs
and Link objects.
"""
if isinstance(url, Link):
url = url.url
url = self.urljoin(url)
return Request(url, callback,
method=method,
headers=headers,
body=body,
cookies=cookies,
meta=meta,
encoding=encoding,
priority=priority,
dont_filter=dont_filter,
errback=errback)

class tutorialDownloaderMiddleware(object):
# 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. @classmethod
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)

def process_request(self, request, spider):
"""修改headers，优先级 1"""
request.headers.setdefault('User-Agent', random.choice(self.agents)) def process_request(self, request, spider):
"""修改cookies，优先级 50"""
request.cookies = self.get_cookies() def process_request(self, request, spider):
"""设置代理，优先级60"""
request.meta['proxy'] = 'http://' + self.proxys[self.num % PROXY_POOL_NUM] def process_response(self, request, response, spider):
"""检查response合法性， 优先级 560"""
html = response.body.decode()
if response.status != 200 or html is None:
print('内容为空')
return request.replace(dont_filter=True)
elif 'VisitRemind' in html:
print('出现验证码')
return request.replace(dont_filter=True)
else:
return response def process_exception(self, request, exception, spider):
"""处理异常，优先级 560"""
print(exception)
meta = request.meta
if 'req_error_times' in meta.keys():
meta['req_error_times'] = meta['req_error_times'] + 1
else:
meta['req_error_times'] = 1
print(meta['req_error_times'])
if meta['req_error_times'] > MAX_ERROR_TIMES:
raise IgnoreRequest
return request.replace(dont_filter=True)