mirror of https://github.com/scrapy/scrapy.git
76 lines
2.9 KiB
Python
76 lines
2.9 KiB
Python
"""
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This module provides some useful functions for working with
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scrapy.http.Response objects
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"""
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import re, weakref
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from twisted.web import http
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from twisted.web.http import RESPONSES
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from scrapy.xlib.BeautifulSoup import BeautifulSoup
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from scrapy.http.response import Response
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def body_or_str(obj, unicode=True):
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assert isinstance(obj, (Response, basestring)), "obj must be Response or basestring, not %s" % type(obj).__name__
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if isinstance(obj, Response):
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return obj.body_as_unicode() if unicode else obj.body
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elif isinstance(obj, str):
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return obj.decode('utf-8') if unicode else obj
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else:
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return obj if unicode else obj.encode('utf-8')
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BASEURL_RE = re.compile(r'<base\s+href\s*=\s*[\"\']\s*([^\"\'\s]+)\s*[\"\']', re.I)
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def get_base_url(response):
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""" Return the base url of the given response used to resolve relative links. """
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# re is used instead of xpath for eficiency reasons. In a quick
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# benchmark using timeit we got (for 50 repetitions) 0.0017 seconds
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# using re and 0.7452 using xpath
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if 'base_url' not in response.cache:
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match = BASEURL_RE.search(response.body[0:4096])
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response.cache['base_url'] = match.group(1) if match else response.url
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return response.cache['base_url']
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META_REFRESH_RE = re.compile(r'<meta[^>]*http-equiv[^>]*refresh[^>].*?(\d+);\s*url=([^"\']+)', re.DOTALL | re.IGNORECASE)
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def get_meta_refresh(response):
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""" Return a tuple of two strings containing the interval and url included
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in the http-equiv parameter of the HTML meta element. If no url is included
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(None, None) is returned [instead of (interval, None)]
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"""
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if 'meta_refresh_url' not in response.cache:
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match = META_REFRESH_RE.search(response.body[0:4096])
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response.cache['meta_refresh_url'] = match.groups() if match else (None, None)
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return response.cache['meta_refresh_url']
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_beautifulsoup_cache = weakref.WeakKeyDictionary()
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def get_cached_beautifulsoup(response):
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"""Return BeautifulSoup object of the given response, with caching
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support"""
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if response not in _beautifulsoup_cache:
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_beautifulsoup_cache[response] = BeautifulSoup(response.body)
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return _beautifulsoup_cache[response]
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def response_status_message(status):
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"""Return status code plus status text descriptive message
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>>> response_status_message(200)
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200 OK
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>>> response_status_message(404)
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404 Not Found
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"""
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return '%s %s' % (status, http.responses.get(int(status)))
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def response_httprepr(response):
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"""Return raw HTTP representation (as string) of the given response. This
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is provided only for reference, since it's not the exact stream of bytes
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that was received (that's not exposed by Twisted).
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"""
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s = "HTTP/1.1 %d %s\r\n" % (response.status, RESPONSES[response.status])
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if response.headers:
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s += response.headers.to_string() + "\r\n"
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s += "\r\n"
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s += response.body
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return s
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