]> jfr.im git - yt-dlp.git/blame_incremental - youtube_dl/extractor/common.py
[youtube] Fix extraction of like and dislike count (fixes #3633)
[yt-dlp.git] / youtube_dl / extractor / common.py
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1from __future__ import unicode_literals
2
3import base64
4import hashlib
5import json
6import netrc
7import os
8import re
9import socket
10import sys
11import time
12import xml.etree.ElementTree
13
14from ..utils import (
15 compat_http_client,
16 compat_urllib_error,
17 compat_urllib_parse_urlparse,
18 compat_str,
19
20 clean_html,
21 compiled_regex_type,
22 ExtractorError,
23 int_or_none,
24 RegexNotFoundError,
25 sanitize_filename,
26 unescapeHTML,
27)
28_NO_DEFAULT = object()
29
30
31class InfoExtractor(object):
32 """Information Extractor class.
33
34 Information extractors are the classes that, given a URL, extract
35 information about the video (or videos) the URL refers to. This
36 information includes the real video URL, the video title, author and
37 others. The information is stored in a dictionary which is then
38 passed to the FileDownloader. The FileDownloader processes this
39 information possibly downloading the video to the file system, among
40 other possible outcomes.
41
42 The dictionaries must include the following fields:
43
44 id: Video identifier.
45 title: Video title, unescaped.
46
47 Additionally, it must contain either a formats entry or a url one:
48
49 formats: A list of dictionaries for each format available, ordered
50 from worst to best quality.
51
52 Potential fields:
53 * url Mandatory. The URL of the video file
54 * ext Will be calculated from url if missing
55 * format A human-readable description of the format
56 ("mp4 container with h264/opus").
57 Calculated from the format_id, width, height.
58 and format_note fields if missing.
59 * format_id A short description of the format
60 ("mp4_h264_opus" or "19").
61 Technically optional, but strongly recommended.
62 * format_note Additional info about the format
63 ("3D" or "DASH video")
64 * width Width of the video, if known
65 * height Height of the video, if known
66 * resolution Textual description of width and height
67 * tbr Average bitrate of audio and video in KBit/s
68 * abr Average audio bitrate in KBit/s
69 * acodec Name of the audio codec in use
70 * asr Audio sampling rate in Hertz
71 * vbr Average video bitrate in KBit/s
72 * vcodec Name of the video codec in use
73 * container Name of the container format
74 * filesize The number of bytes, if known in advance
75 * filesize_approx An estimate for the number of bytes
76 * player_url SWF Player URL (used for rtmpdump).
77 * protocol The protocol that will be used for the actual
78 download, lower-case.
79 "http", "https", "rtsp", "rtmp", "m3u8" or so.
80 * preference Order number of this format. If this field is
81 present and not None, the formats get sorted
82 by this field, regardless of all other values.
83 -1 for default (order by other properties),
84 -2 or smaller for less than default.
85 * quality Order number of the video quality of this
86 format, irrespective of the file format.
87 -1 for default (order by other properties),
88 -2 or smaller for less than default.
89 * http_referer HTTP Referer header value to set.
90 * http_method HTTP method to use for the download.
91 * http_headers A dictionary of additional HTTP headers
92 to add to the request.
93 * http_post_data Additional data to send with a POST
94 request.
95 url: Final video URL.
96 ext: Video filename extension.
97 format: The video format, defaults to ext (used for --get-format)
98 player_url: SWF Player URL (used for rtmpdump).
99
100 The following fields are optional:
101
102 display_id An alternative identifier for the video, not necessarily
103 unique, but available before title. Typically, id is
104 something like "4234987", title "Dancing naked mole rats",
105 and display_id "dancing-naked-mole-rats"
106 thumbnails: A list of dictionaries, with the following entries:
107 * "url"
108 * "width" (optional, int)
109 * "height" (optional, int)
110 * "resolution" (optional, string "{width}x{height"},
111 deprecated)
112 thumbnail: Full URL to a video thumbnail image.
113 description: One-line video description.
114 uploader: Full name of the video uploader.
115 timestamp: UNIX timestamp of the moment the video became available.
116 upload_date: Video upload date (YYYYMMDD).
117 If not explicitly set, calculated from timestamp.
118 uploader_id: Nickname or id of the video uploader.
119 location: Physical location where the video was filmed.
120 subtitles: The subtitle file contents as a dictionary in the format
121 {language: subtitles}.
122 duration: Length of the video in seconds, as an integer.
123 view_count: How many users have watched the video on the platform.
124 like_count: Number of positive ratings of the video
125 dislike_count: Number of negative ratings of the video
126 comment_count: Number of comments on the video
127 age_limit: Age restriction for the video, as an integer (years)
128 webpage_url: The url to the video webpage, if given to youtube-dl it
129 should allow to get the same result again. (It will be set
130 by YoutubeDL if it's missing)
131 categories: A list of categories that the video falls in, for example
132 ["Sports", "Berlin"]
133
134 Unless mentioned otherwise, the fields should be Unicode strings.
135
136 Subclasses of this one should re-define the _real_initialize() and
137 _real_extract() methods and define a _VALID_URL regexp.
138 Probably, they should also be added to the list of extractors.
139
140 Finally, the _WORKING attribute should be set to False for broken IEs
141 in order to warn the users and skip the tests.
142 """
143
144 _ready = False
145 _downloader = None
146 _WORKING = True
147
148 def __init__(self, downloader=None):
149 """Constructor. Receives an optional downloader."""
150 self._ready = False
151 self.set_downloader(downloader)
152
153 @classmethod
154 def suitable(cls, url):
155 """Receives a URL and returns True if suitable for this IE."""
156
157 # This does not use has/getattr intentionally - we want to know whether
158 # we have cached the regexp for *this* class, whereas getattr would also
159 # match the superclass
160 if '_VALID_URL_RE' not in cls.__dict__:
161 cls._VALID_URL_RE = re.compile(cls._VALID_URL)
162 return cls._VALID_URL_RE.match(url) is not None
163
164 @classmethod
165 def working(cls):
166 """Getter method for _WORKING."""
167 return cls._WORKING
168
169 def initialize(self):
170 """Initializes an instance (authentication, etc)."""
171 if not self._ready:
172 self._real_initialize()
173 self._ready = True
174
175 def extract(self, url):
176 """Extracts URL information and returns it in list of dicts."""
177 self.initialize()
178 return self._real_extract(url)
179
180 def set_downloader(self, downloader):
181 """Sets the downloader for this IE."""
182 self._downloader = downloader
183
184 def _real_initialize(self):
185 """Real initialization process. Redefine in subclasses."""
186 pass
187
188 def _real_extract(self, url):
189 """Real extraction process. Redefine in subclasses."""
190 pass
191
192 @classmethod
193 def ie_key(cls):
194 """A string for getting the InfoExtractor with get_info_extractor"""
195 return cls.__name__[:-2]
196
197 @property
198 def IE_NAME(self):
199 return type(self).__name__[:-2]
200
201 def _request_webpage(self, url_or_request, video_id, note=None, errnote=None, fatal=True):
202 """ Returns the response handle """
203 if note is None:
204 self.report_download_webpage(video_id)
205 elif note is not False:
206 if video_id is None:
207 self.to_screen('%s' % (note,))
208 else:
209 self.to_screen('%s: %s' % (video_id, note))
210 try:
211 return self._downloader.urlopen(url_or_request)
212 except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
213 if errnote is False:
214 return False
215 if errnote is None:
216 errnote = 'Unable to download webpage'
217 errmsg = '%s: %s' % (errnote, compat_str(err))
218 if fatal:
219 raise ExtractorError(errmsg, sys.exc_info()[2], cause=err)
220 else:
221 self._downloader.report_warning(errmsg)
222 return False
223
224 def _download_webpage_handle(self, url_or_request, video_id, note=None, errnote=None, fatal=True):
225 """ Returns a tuple (page content as string, URL handle) """
226
227 # Strip hashes from the URL (#1038)
228 if isinstance(url_or_request, (compat_str, str)):
229 url_or_request = url_or_request.partition('#')[0]
230
231 urlh = self._request_webpage(url_or_request, video_id, note, errnote, fatal)
232 if urlh is False:
233 assert not fatal
234 return False
235 content_type = urlh.headers.get('Content-Type', '')
236 webpage_bytes = urlh.read()
237 m = re.match(r'[a-zA-Z0-9_.-]+/[a-zA-Z0-9_.-]+\s*;\s*charset=(.+)', content_type)
238 if m:
239 encoding = m.group(1)
240 else:
241 m = re.search(br'<meta[^>]+charset=[\'"]?([^\'")]+)[ /\'">]',
242 webpage_bytes[:1024])
243 if m:
244 encoding = m.group(1).decode('ascii')
245 elif webpage_bytes.startswith(b'\xff\xfe'):
246 encoding = 'utf-16'
247 else:
248 encoding = 'utf-8'
249 if self._downloader.params.get('dump_intermediate_pages', False):
250 try:
251 url = url_or_request.get_full_url()
252 except AttributeError:
253 url = url_or_request
254 self.to_screen('Dumping request to ' + url)
255 dump = base64.b64encode(webpage_bytes).decode('ascii')
256 self._downloader.to_screen(dump)
257 if self._downloader.params.get('write_pages', False):
258 try:
259 url = url_or_request.get_full_url()
260 except AttributeError:
261 url = url_or_request
262 basen = '%s_%s' % (video_id, url)
263 if len(basen) > 240:
264 h = '___' + hashlib.md5(basen.encode('utf-8')).hexdigest()
265 basen = basen[:240 - len(h)] + h
266 raw_filename = basen + '.dump'
267 filename = sanitize_filename(raw_filename, restricted=True)
268 self.to_screen('Saving request to ' + filename)
269 with open(filename, 'wb') as outf:
270 outf.write(webpage_bytes)
271
272 try:
273 content = webpage_bytes.decode(encoding, 'replace')
274 except LookupError:
275 content = webpage_bytes.decode('utf-8', 'replace')
276
277 if ('<title>Access to this site is blocked</title>' in content and
278 'Websense' in content[:512]):
279 msg = 'Access to this webpage has been blocked by Websense filtering software in your network.'
280 blocked_iframe = self._html_search_regex(
281 r'<iframe src="([^"]+)"', content,
282 'Websense information URL', default=None)
283 if blocked_iframe:
284 msg += ' Visit %s for more details' % blocked_iframe
285 raise ExtractorError(msg, expected=True)
286
287 return (content, urlh)
288
289 def _download_webpage(self, url_or_request, video_id, note=None, errnote=None, fatal=True):
290 """ Returns the data of the page as a string """
291 res = self._download_webpage_handle(url_or_request, video_id, note, errnote, fatal)
292 if res is False:
293 return res
294 else:
295 content, _ = res
296 return content
297
298 def _download_xml(self, url_or_request, video_id,
299 note='Downloading XML', errnote='Unable to download XML',
300 transform_source=None, fatal=True):
301 """Return the xml as an xml.etree.ElementTree.Element"""
302 xml_string = self._download_webpage(
303 url_or_request, video_id, note, errnote, fatal=fatal)
304 if xml_string is False:
305 return xml_string
306 if transform_source:
307 xml_string = transform_source(xml_string)
308 return xml.etree.ElementTree.fromstring(xml_string.encode('utf-8'))
309
310 def _download_json(self, url_or_request, video_id,
311 note='Downloading JSON metadata',
312 errnote='Unable to download JSON metadata',
313 transform_source=None,
314 fatal=True):
315 json_string = self._download_webpage(
316 url_or_request, video_id, note, errnote, fatal=fatal)
317 if (not fatal) and json_string is False:
318 return None
319 if transform_source:
320 json_string = transform_source(json_string)
321 try:
322 return json.loads(json_string)
323 except ValueError as ve:
324 raise ExtractorError('Failed to download JSON', cause=ve)
325
326 def report_warning(self, msg, video_id=None):
327 idstr = '' if video_id is None else '%s: ' % video_id
328 self._downloader.report_warning(
329 '[%s] %s%s' % (self.IE_NAME, idstr, msg))
330
331 def to_screen(self, msg):
332 """Print msg to screen, prefixing it with '[ie_name]'"""
333 self._downloader.to_screen('[%s] %s' % (self.IE_NAME, msg))
334
335 def report_extraction(self, id_or_name):
336 """Report information extraction."""
337 self.to_screen('%s: Extracting information' % id_or_name)
338
339 def report_download_webpage(self, video_id):
340 """Report webpage download."""
341 self.to_screen('%s: Downloading webpage' % video_id)
342
343 def report_age_confirmation(self):
344 """Report attempt to confirm age."""
345 self.to_screen('Confirming age')
346
347 def report_login(self):
348 """Report attempt to log in."""
349 self.to_screen('Logging in')
350
351 #Methods for following #608
352 @staticmethod
353 def url_result(url, ie=None, video_id=None):
354 """Returns a url that points to a page that should be processed"""
355 #TODO: ie should be the class used for getting the info
356 video_info = {'_type': 'url',
357 'url': url,
358 'ie_key': ie}
359 if video_id is not None:
360 video_info['id'] = video_id
361 return video_info
362 @staticmethod
363 def playlist_result(entries, playlist_id=None, playlist_title=None):
364 """Returns a playlist"""
365 video_info = {'_type': 'playlist',
366 'entries': entries}
367 if playlist_id:
368 video_info['id'] = playlist_id
369 if playlist_title:
370 video_info['title'] = playlist_title
371 return video_info
372
373 def _search_regex(self, pattern, string, name, default=_NO_DEFAULT, fatal=True, flags=0):
374 """
375 Perform a regex search on the given string, using a single or a list of
376 patterns returning the first matching group.
377 In case of failure return a default value or raise a WARNING or a
378 RegexNotFoundError, depending on fatal, specifying the field name.
379 """
380 if isinstance(pattern, (str, compat_str, compiled_regex_type)):
381 mobj = re.search(pattern, string, flags)
382 else:
383 for p in pattern:
384 mobj = re.search(p, string, flags)
385 if mobj:
386 break
387
388 if os.name != 'nt' and sys.stderr.isatty():
389 _name = '\033[0;34m%s\033[0m' % name
390 else:
391 _name = name
392
393 if mobj:
394 # return the first matching group
395 return next(g for g in mobj.groups() if g is not None)
396 elif default is not _NO_DEFAULT:
397 return default
398 elif fatal:
399 raise RegexNotFoundError('Unable to extract %s' % _name)
400 else:
401 self._downloader.report_warning('unable to extract %s; '
402 'please report this issue on http://yt-dl.org/bug' % _name)
403 return None
404
405 def _html_search_regex(self, pattern, string, name, default=_NO_DEFAULT, fatal=True, flags=0):
406 """
407 Like _search_regex, but strips HTML tags and unescapes entities.
408 """
409 res = self._search_regex(pattern, string, name, default, fatal, flags)
410 if res:
411 return clean_html(res).strip()
412 else:
413 return res
414
415 def _get_login_info(self):
416 """
417 Get the the login info as (username, password)
418 It will look in the netrc file using the _NETRC_MACHINE value
419 If there's no info available, return (None, None)
420 """
421 if self._downloader is None:
422 return (None, None)
423
424 username = None
425 password = None
426 downloader_params = self._downloader.params
427
428 # Attempt to use provided username and password or .netrc data
429 if downloader_params.get('username', None) is not None:
430 username = downloader_params['username']
431 password = downloader_params['password']
432 elif downloader_params.get('usenetrc', False):
433 try:
434 info = netrc.netrc().authenticators(self._NETRC_MACHINE)
435 if info is not None:
436 username = info[0]
437 password = info[2]
438 else:
439 raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
440 except (IOError, netrc.NetrcParseError) as err:
441 self._downloader.report_warning('parsing .netrc: %s' % compat_str(err))
442
443 return (username, password)
444
445 def _get_tfa_info(self):
446 """
447 Get the two-factor authentication info
448 TODO - asking the user will be required for sms/phone verify
449 currently just uses the command line option
450 If there's no info available, return None
451 """
452 if self._downloader is None:
453 return None
454 downloader_params = self._downloader.params
455
456 if downloader_params.get('twofactor', None) is not None:
457 return downloader_params['twofactor']
458
459 return None
460
461 # Helper functions for extracting OpenGraph info
462 @staticmethod
463 def _og_regexes(prop):
464 content_re = r'content=(?:"([^>]+?)"|\'([^>]+?)\')'
465 property_re = r'(?:name|property)=[\'"]og:%s[\'"]' % re.escape(prop)
466 template = r'<meta[^>]+?%s[^>]+?%s'
467 return [
468 template % (property_re, content_re),
469 template % (content_re, property_re),
470 ]
471
472 def _og_search_property(self, prop, html, name=None, **kargs):
473 if name is None:
474 name = 'OpenGraph %s' % prop
475 escaped = self._search_regex(self._og_regexes(prop), html, name, flags=re.DOTALL, **kargs)
476 if escaped is None:
477 return None
478 return unescapeHTML(escaped)
479
480 def _og_search_thumbnail(self, html, **kargs):
481 return self._og_search_property('image', html, 'thumbnail url', fatal=False, **kargs)
482
483 def _og_search_description(self, html, **kargs):
484 return self._og_search_property('description', html, fatal=False, **kargs)
485
486 def _og_search_title(self, html, **kargs):
487 return self._og_search_property('title', html, **kargs)
488
489 def _og_search_video_url(self, html, name='video url', secure=True, **kargs):
490 regexes = self._og_regexes('video') + self._og_regexes('video:url')
491 if secure:
492 regexes = self._og_regexes('video:secure_url') + regexes
493 return self._html_search_regex(regexes, html, name, **kargs)
494
495 def _og_search_url(self, html, **kargs):
496 return self._og_search_property('url', html, **kargs)
497
498 def _html_search_meta(self, name, html, display_name=None, fatal=False, **kwargs):
499 if display_name is None:
500 display_name = name
501 return self._html_search_regex(
502 r'''(?ix)<meta
503 (?=[^>]+(?:itemprop|name|property)=["\']?%s["\']?)
504 [^>]+content=["\']([^"\']+)["\']''' % re.escape(name),
505 html, display_name, fatal=fatal, **kwargs)
506
507 def _dc_search_uploader(self, html):
508 return self._html_search_meta('dc.creator', html, 'uploader')
509
510 def _rta_search(self, html):
511 # See http://www.rtalabel.org/index.php?content=howtofaq#single
512 if re.search(r'(?ix)<meta\s+name="rating"\s+'
513 r' content="RTA-5042-1996-1400-1577-RTA"',
514 html):
515 return 18
516 return 0
517
518 def _media_rating_search(self, html):
519 # See http://www.tjg-designs.com/WP/metadata-code-examples-adding-metadata-to-your-web-pages/
520 rating = self._html_search_meta('rating', html)
521
522 if not rating:
523 return None
524
525 RATING_TABLE = {
526 'safe for kids': 0,
527 'general': 8,
528 '14 years': 14,
529 'mature': 17,
530 'restricted': 19,
531 }
532 return RATING_TABLE.get(rating.lower(), None)
533
534 def _twitter_search_player(self, html):
535 return self._html_search_meta('twitter:player', html,
536 'twitter card player')
537
538 def _sort_formats(self, formats):
539 if not formats:
540 raise ExtractorError('No video formats found')
541
542 def _formats_key(f):
543 # TODO remove the following workaround
544 from ..utils import determine_ext
545 if not f.get('ext') and 'url' in f:
546 f['ext'] = determine_ext(f['url'])
547
548 preference = f.get('preference')
549 if preference is None:
550 proto = f.get('protocol')
551 if proto is None:
552 proto = compat_urllib_parse_urlparse(f.get('url', '')).scheme
553
554 preference = 0 if proto in ['http', 'https'] else -0.1
555 if f.get('ext') in ['f4f', 'f4m']: # Not yet supported
556 preference -= 0.5
557
558 if f.get('vcodec') == 'none': # audio only
559 if self._downloader.params.get('prefer_free_formats'):
560 ORDER = ['aac', 'mp3', 'm4a', 'webm', 'ogg', 'opus']
561 else:
562 ORDER = ['webm', 'opus', 'ogg', 'mp3', 'aac', 'm4a']
563 ext_preference = 0
564 try:
565 audio_ext_preference = ORDER.index(f['ext'])
566 except ValueError:
567 audio_ext_preference = -1
568 else:
569 if self._downloader.params.get('prefer_free_formats'):
570 ORDER = ['flv', 'mp4', 'webm']
571 else:
572 ORDER = ['webm', 'flv', 'mp4']
573 try:
574 ext_preference = ORDER.index(f['ext'])
575 except ValueError:
576 ext_preference = -1
577 audio_ext_preference = 0
578
579 return (
580 preference,
581 f.get('quality') if f.get('quality') is not None else -1,
582 f.get('height') if f.get('height') is not None else -1,
583 f.get('width') if f.get('width') is not None else -1,
584 ext_preference,
585 f.get('tbr') if f.get('tbr') is not None else -1,
586 f.get('vbr') if f.get('vbr') is not None else -1,
587 f.get('abr') if f.get('abr') is not None else -1,
588 audio_ext_preference,
589 f.get('filesize') if f.get('filesize') is not None else -1,
590 f.get('filesize_approx') if f.get('filesize_approx') is not None else -1,
591 f.get('format_id'),
592 )
593 formats.sort(key=_formats_key)
594
595 def http_scheme(self):
596 """ Either "https:" or "https:", depending on the user's preferences """
597 return (
598 'http:'
599 if self._downloader.params.get('prefer_insecure', False)
600 else 'https:')
601
602 def _proto_relative_url(self, url, scheme=None):
603 if url is None:
604 return url
605 if url.startswith('//'):
606 if scheme is None:
607 scheme = self.http_scheme()
608 return scheme + url
609 else:
610 return url
611
612 def _sleep(self, timeout, video_id, msg_template=None):
613 if msg_template is None:
614 msg_template = '%(video_id)s: Waiting for %(timeout)s seconds'
615 msg = msg_template % {'video_id': video_id, 'timeout': timeout}
616 self.to_screen(msg)
617 time.sleep(timeout)
618
619 def _extract_f4m_formats(self, manifest_url, video_id):
620 manifest = self._download_xml(
621 manifest_url, video_id, 'Downloading f4m manifest',
622 'Unable to download f4m manifest')
623
624 formats = []
625 media_nodes = manifest.findall('{http://ns.adobe.com/f4m/1.0}media')
626 for i, media_el in enumerate(media_nodes):
627 tbr = int_or_none(media_el.attrib.get('bitrate'))
628 format_id = 'f4m-%d' % (i if tbr is None else tbr)
629 formats.append({
630 'format_id': format_id,
631 'url': manifest_url,
632 'ext': 'flv',
633 'tbr': tbr,
634 'width': int_or_none(media_el.attrib.get('width')),
635 'height': int_or_none(media_el.attrib.get('height')),
636 })
637 self._sort_formats(formats)
638
639 return formats
640
641 def _extract_m3u8_formats(self, m3u8_url, video_id, ext=None):
642 formats = [{
643 'format_id': 'm3u8-meta',
644 'url': m3u8_url,
645 'ext': ext,
646 'protocol': 'm3u8',
647 'preference': -1,
648 'resolution': 'multiple',
649 'format_note': 'Quality selection URL',
650 }]
651
652 m3u8_doc = self._download_webpage(m3u8_url, video_id)
653 last_info = None
654 kv_rex = re.compile(
655 r'(?P<key>[a-zA-Z_-]+)=(?P<val>"[^"]+"|[^",]+)(?:,|$)')
656 for line in m3u8_doc.splitlines():
657 if line.startswith('#EXT-X-STREAM-INF:'):
658 last_info = {}
659 for m in kv_rex.finditer(line):
660 v = m.group('val')
661 if v.startswith('"'):
662 v = v[1:-1]
663 last_info[m.group('key')] = v
664 elif line.startswith('#') or not line.strip():
665 continue
666 else:
667 if last_info is None:
668 formats.append({'url': line})
669 continue
670 tbr = int_or_none(last_info.get('BANDWIDTH'), scale=1000)
671
672 f = {
673 'format_id': 'm3u8-%d' % (tbr if tbr else len(formats)),
674 'url': line.strip(),
675 'tbr': tbr,
676 'ext': ext,
677 }
678 codecs = last_info.get('CODECS')
679 if codecs:
680 video, audio = codecs.split(',')
681 f['vcodec'] = video.partition('.')[0]
682 f['acodec'] = audio.partition('.')[0]
683 resolution = last_info.get('RESOLUTION')
684 if resolution:
685 width_str, height_str = resolution.split('x')
686 f['width'] = int(width_str)
687 f['height'] = int(height_str)
688 formats.append(f)
689 last_info = {}
690 self._sort_formats(formats)
691 return formats
692
693
694class SearchInfoExtractor(InfoExtractor):
695 """
696 Base class for paged search queries extractors.
697 They accept urls in the format _SEARCH_KEY(|all|[0-9]):{query}
698 Instances should define _SEARCH_KEY and _MAX_RESULTS.
699 """
700
701 @classmethod
702 def _make_valid_url(cls):
703 return r'%s(?P<prefix>|[1-9][0-9]*|all):(?P<query>[\s\S]+)' % cls._SEARCH_KEY
704
705 @classmethod
706 def suitable(cls, url):
707 return re.match(cls._make_valid_url(), url) is not None
708
709 def _real_extract(self, query):
710 mobj = re.match(self._make_valid_url(), query)
711 if mobj is None:
712 raise ExtractorError('Invalid search query "%s"' % query)
713
714 prefix = mobj.group('prefix')
715 query = mobj.group('query')
716 if prefix == '':
717 return self._get_n_results(query, 1)
718 elif prefix == 'all':
719 return self._get_n_results(query, self._MAX_RESULTS)
720 else:
721 n = int(prefix)
722 if n <= 0:
723 raise ExtractorError('invalid download number %s for query "%s"' % (n, query))
724 elif n > self._MAX_RESULTS:
725 self._downloader.report_warning('%s returns max %i results (you requested %i)' % (self._SEARCH_KEY, self._MAX_RESULTS, n))
726 n = self._MAX_RESULTS
727 return self._get_n_results(query, n)
728
729 def _get_n_results(self, query, n):
730 """Get a specified number of results for a query"""
731 raise NotImplementedError("This method must be implemented by subclasses")
732
733 @property
734 def SEARCH_KEY(self):
735 return self._SEARCH_KEY