1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
"""
This module implements the TextResponse class which adds encoding handling and
discovering (through HTTP headers) to base Response class.
See documentation in docs/topics/request-response.rst
"""
import six
from six.moves.urllib.parse import urljoin
import parsel
from w3lib.encoding import html_to_unicode, resolve_encoding, \
html_body_declared_encoding, http_content_type_encoding
from w3lib.html import strip_html5_whitespace
from scrapy.http.request import Request
from scrapy.http.response import Response
from scrapy.utils.response import get_base_url
from scrapy.utils.python import memoizemethod_noargs, to_native_str
class TextResponse(Response):
_DEFAULT_ENCODING = 'ascii'
def __init__(self, *args, **kwargs):
self._encoding = kwargs.pop('encoding', None)
self._cached_benc = None
self._cached_ubody = None
self._cached_selector = None
super(TextResponse, self).__init__(*args, **kwargs)
def _set_url(self, url):
if isinstance(url, six.text_type):
if six.PY2 and self.encoding is None:
raise TypeError("Cannot convert unicode url - %s "
"has no encoding" % type(self).__name__)
self._url = to_native_str(url, self.encoding)
else:
super(TextResponse, self)._set_url(url)
def _set_body(self, body):
self._body = b'' # used by encoding detection
if isinstance(body, six.text_type):
if self._encoding is None:
raise TypeError('Cannot convert unicode body - %s has no encoding' %
type(self).__name__)
self._body = body.encode(self._encoding)
else:
super(TextResponse, self)._set_body(body)
def replace(self, *args, **kwargs):
kwargs.setdefault('encoding', self.encoding)
return Response.replace(self, *args, **kwargs)
@property
def encoding(self):
return self._declared_encoding() or self._body_inferred_encoding()
def _declared_encoding(self):
return self._encoding or self._headers_encoding() \
or self._body_declared_encoding()
def body_as_unicode(self):
"""Return body as unicode"""
return self.text
@property
def text(self):
""" Body as unicode """
# access self.encoding before _cached_ubody to make sure
# _body_inferred_encoding is called
benc = self.encoding
if self._cached_ubody is None:
charset = 'charset=%s' % benc
self._cached_ubody = html_to_unicode(charset, self.body)[1]
return self._cached_ubody
def urljoin(self, url):
"""Join this Response's url with a possible relative url to form an
absolute interpretation of the latter."""
return urljoin(get_base_url(self), url)
@memoizemethod_noargs
def _headers_encoding(self):
content_type = self.headers.get(b'Content-Type', b'')
return http_content_type_encoding(to_native_str(content_type))
def _body_inferred_encoding(self):
if self._cached_benc is None:
content_type = to_native_str(self.headers.get(b'Content-Type', b''))
benc, ubody = html_to_unicode(content_type, self.body,
auto_detect_fun=self._auto_detect_fun,
default_encoding=self._DEFAULT_ENCODING)
self._cached_benc = benc
self._cached_ubody = ubody
return self._cached_benc
def _auto_detect_fun(self, text):
for enc in (self._DEFAULT_ENCODING, 'utf-8', 'cp1252'):
try:
text.decode(enc)
except UnicodeError:
continue
return resolve_encoding(enc)
@memoizemethod_noargs
def _body_declared_encoding(self):
return html_body_declared_encoding(self.body)
@property
def selector(self):
from scrapy.selector import Selector
if self._cached_selector is None:
self._cached_selector = Selector(self)
return self._cached_selector
def xpath(self, query, **kwargs):
return self.selector.xpath(query, **kwargs)
def css(self, query):
return self.selector.css(query)
def follow(self, url, callback=None, method='GET', headers=None, body=None,
cookies=None, meta=None, encoding=None, 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 not only an absolute URL, but also
* a relative URL;
* a scrapy.link.Link object (e.g. a link extractor result);
* an attribute Selector (not SelectorList) - e.g.
``response.css('a::attr(href)')[0]`` or
``response.xpath('//img/@src')[0]``.
* a Selector for ``<a>`` or ``<link>`` element, e.g.
``response.css('a.my_link')[0]``.
See :ref:`response-follow-example` for usage examples.
"""
if isinstance(url, parsel.Selector):
url = _url_from_selector(url)
elif isinstance(url, parsel.SelectorList):
raise ValueError("SelectorList is not supported")
encoding = self.encoding if encoding is None else encoding
return super(TextResponse, self).follow(url, callback,
method=method,
headers=headers,
body=body,
cookies=cookies,
meta=meta,
encoding=encoding,
priority=priority,
dont_filter=dont_filter,
errback=errback
)
def _url_from_selector(sel):
# type: (parsel.Selector) -> str
if isinstance(sel.root, six.string_types):
# e.g. ::attr(href) result
return strip_html5_whitespace(sel.root)
if not hasattr(sel.root, 'tag'):
raise ValueError("Unsupported selector: %s" % sel)
if sel.root.tag not in ('a', 'link'):
raise ValueError("Only <a> and <link> elements are supported; got <%s>" %
sel.root.tag)
href = sel.root.get('href')
if href is None:
raise ValueError("<%s> element has no href attribute: %s" %
(sel.root.tag, sel))
return strip_html5_whitespace(href)
|
