Use character instead of byte strings
[youtube-dl] / youtube_dl / utils.py
1 #!/usr/bin/env python
2 # -*- coding: utf-8 -*-
3
4 import gzip
5 import htmlentitydefs
6 import HTMLParser
7 import locale
8 import os
9 import re
10 import sys
11 import zlib
12 import urllib2
13 import email.utils
14 import json
15
16 try:
17         import cStringIO as StringIO
18 except ImportError:
19         import StringIO
20
21 std_headers = {
22         'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20100101 Firefox/10.0',
23         'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
24         'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
25         'Accept-Encoding': 'gzip, deflate',
26         'Accept-Language': 'en-us,en;q=0.5',
27 }
28
29 try:
30     compat_str = unicode # Python 2
31 except NameError:
32     compat_str = str
33
34 def preferredencoding():
35         """Get preferred encoding.
36
37         Returns the best encoding scheme for the system, based on
38         locale.getpreferredencoding() and some further tweaks.
39         """
40         def yield_preferredencoding():
41                 try:
42                         pref = locale.getpreferredencoding()
43                         u'TEST'.encode(pref)
44                 except:
45                         pref = 'UTF-8'
46                 while True:
47                         yield pref
48         return yield_preferredencoding().next()
49
50
51 def htmlentity_transform(matchobj):
52         """Transforms an HTML entity to a Unicode character.
53
54         This function receives a match object and is intended to be used with
55         the re.sub() function.
56         """
57         entity = matchobj.group(1)
58
59         # Known non-numeric HTML entity
60         if entity in htmlentitydefs.name2codepoint:
61                 return unichr(htmlentitydefs.name2codepoint[entity])
62
63         # Unicode character
64         mobj = re.match(ur'(?u)#(x?\d+)', entity)
65         if mobj is not None:
66                 numstr = mobj.group(1)
67                 if numstr.startswith(u'x'):
68                         base = 16
69                         numstr = u'0%s' % numstr
70                 else:
71                         base = 10
72                 return unichr(long(numstr, base))
73
74         # Unknown entity in name, return its literal representation
75         return (u'&%s;' % entity)
76
77 HTMLParser.locatestarttagend = re.compile(r"""<[a-zA-Z][-.a-zA-Z0-9:_]*(?:\s+(?:(?<=['"\s])[^\s/>][^\s/=>]*(?:\s*=+\s*(?:'[^']*'|"[^"]*"|(?!['"])[^>\s]*))?\s*)*)?\s*""", re.VERBOSE) # backport bugfix
78 class IDParser(HTMLParser.HTMLParser):
79         """Modified HTMLParser that isolates a tag with the specified id"""
80         def __init__(self, id):
81                 self.id = id
82                 self.result = None
83                 self.started = False
84                 self.depth = {}
85                 self.html = None
86                 self.watch_startpos = False
87                 self.error_count = 0
88                 HTMLParser.HTMLParser.__init__(self)
89
90         def error(self, message):
91                 if self.error_count > 10 or self.started:
92                         raise HTMLParser.HTMLParseError(message, self.getpos())
93                 self.rawdata = '\n'.join(self.html.split('\n')[self.getpos()[0]:]) # skip one line
94                 self.error_count += 1
95                 self.goahead(1)
96
97         def loads(self, html):
98                 self.html = html
99                 self.feed(html)
100                 self.close()
101
102         def handle_starttag(self, tag, attrs):
103                 attrs = dict(attrs)
104                 if self.started:
105                         self.find_startpos(None)
106                 if 'id' in attrs and attrs['id'] == self.id:
107                         self.result = [tag]
108                         self.started = True
109                         self.watch_startpos = True
110                 if self.started:
111                         if not tag in self.depth: self.depth[tag] = 0
112                         self.depth[tag] += 1
113
114         def handle_endtag(self, tag):
115                 if self.started:
116                         if tag in self.depth: self.depth[tag] -= 1
117                         if self.depth[self.result[0]] == 0:
118                                 self.started = False
119                                 self.result.append(self.getpos())
120
121         def find_startpos(self, x):
122                 """Needed to put the start position of the result (self.result[1])
123                 after the opening tag with the requested id"""
124                 if self.watch_startpos:
125                         self.watch_startpos = False
126                         self.result.append(self.getpos())
127         handle_entityref = handle_charref = handle_data = handle_comment = \
128         handle_decl = handle_pi = unknown_decl = find_startpos
129
130         def get_result(self):
131                 if self.result == None: return None
132                 if len(self.result) != 3: return None
133                 lines = self.html.split('\n')
134                 lines = lines[self.result[1][0]-1:self.result[2][0]]
135                 lines[0] = lines[0][self.result[1][1]:]
136                 if len(lines) == 1:
137                         lines[-1] = lines[-1][:self.result[2][1]-self.result[1][1]]
138                 lines[-1] = lines[-1][:self.result[2][1]]
139                 return '\n'.join(lines).strip()
140
141 def get_element_by_id(id, html):
142         """Return the content of the tag with the specified id in the passed HTML document"""
143         parser = IDParser(id)
144         try:
145                 parser.loads(html)
146         except HTMLParser.HTMLParseError:
147                 pass
148         return parser.get_result()
149
150
151 def clean_html(html):
152         """Clean an HTML snippet into a readable string"""
153         # Newline vs <br />
154         html = html.replace('\n', ' ')
155         html = re.sub('\s*<\s*br\s*/?\s*>\s*', '\n', html)
156         # Strip html tags
157         html = re.sub('<.*?>', '', html)
158         # Replace html entities
159         html = unescapeHTML(html)
160         return html
161
162
163 def sanitize_open(filename, open_mode):
164         """Try to open the given filename, and slightly tweak it if this fails.
165
166         Attempts to open the given filename. If this fails, it tries to change
167         the filename slightly, step by step, until it's either able to open it
168         or it fails and raises a final exception, like the standard open()
169         function.
170
171         It returns the tuple (stream, definitive_file_name).
172         """
173         try:
174                 if filename == u'-':
175                         if sys.platform == 'win32':
176                                 import msvcrt
177                                 msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
178                         return (sys.stdout, filename)
179                 stream = open(encodeFilename(filename), open_mode)
180                 return (stream, filename)
181         except (IOError, OSError), err:
182                 # In case of error, try to remove win32 forbidden chars
183                 filename = re.sub(ur'[/<>:"\|\?\*]', u'#', filename)
184
185                 # An exception here should be caught in the caller
186                 stream = open(encodeFilename(filename), open_mode)
187                 return (stream, filename)
188
189
190 def timeconvert(timestr):
191         """Convert RFC 2822 defined time string into system timestamp"""
192         timestamp = None
193         timetuple = email.utils.parsedate_tz(timestr)
194         if timetuple is not None:
195                 timestamp = email.utils.mktime_tz(timetuple)
196         return timestamp
197         
198 def sanitize_filename(s):
199         """Sanitizes a string so it could be used as part of a filename."""
200         def replace_insane(char):
201                 if char == '?' or ord(char) < 32 or ord(char) == 127:
202                         return ''
203                 elif char == '"':
204                         return '\''
205                 elif char == ':':
206                         return ' -'
207                 elif char in '\\/|*<>':
208                         return '-'
209                 return char
210
211         result = u''.join(map(replace_insane, s))
212         while '--' in result:
213                 result = result.replace('--', '-')
214         return result.strip('-')
215
216 def orderedSet(iterable):
217         """ Remove all duplicates from the input iterable """
218         res = []
219         for el in iterable:
220                 if el not in res:
221                         res.append(el)
222         return res
223
224 def unescapeHTML(s):
225         """
226         @param s a string (of type unicode)
227         """
228         assert type(s) == type(u'')
229
230         result = re.sub(ur'(?u)&(.+?);', htmlentity_transform, s)
231         return result
232
233 def encodeFilename(s):
234         """
235         @param s The name of the file (of type unicode)
236         """
237
238         assert type(s) == type(u'')
239
240         if sys.platform == 'win32' and sys.getwindowsversion()[0] >= 5:
241                 # Pass u'' directly to use Unicode APIs on Windows 2000 and up
242                 # (Detecting Windows NT 4 is tricky because 'major >= 4' would
243                 # match Windows 9x series as well. Besides, NT 4 is obsolete.)
244                 return s
245         else:
246                 return s.encode(sys.getfilesystemencoding(), 'ignore')
247
248 class DownloadError(Exception):
249         """Download Error exception.
250
251         This exception may be thrown by FileDownloader objects if they are not
252         configured to continue on errors. They will contain the appropriate
253         error message.
254         """
255         pass
256
257
258 class SameFileError(Exception):
259         """Same File exception.
260
261         This exception will be thrown by FileDownloader objects if they detect
262         multiple files would have to be downloaded to the same file on disk.
263         """
264         pass
265
266
267 class PostProcessingError(Exception):
268         """Post Processing exception.
269
270         This exception may be raised by PostProcessor's .run() method to
271         indicate an error in the postprocessing task.
272         """
273         pass
274
275 class MaxDownloadsReached(Exception):
276         """ --max-downloads limit has been reached. """
277         pass
278
279
280 class UnavailableVideoError(Exception):
281         """Unavailable Format exception.
282
283         This exception will be thrown when a video is requested
284         in a format that is not available for that video.
285         """
286         pass
287
288
289 class ContentTooShortError(Exception):
290         """Content Too Short exception.
291
292         This exception may be raised by FileDownloader objects when a file they
293         download is too small for what the server announced first, indicating
294         the connection was probably interrupted.
295         """
296         # Both in bytes
297         downloaded = None
298         expected = None
299
300         def __init__(self, downloaded, expected):
301                 self.downloaded = downloaded
302                 self.expected = expected
303
304
305 class Trouble(Exception):
306         """Trouble helper exception
307         
308         This is an exception to be handled with
309         FileDownloader.trouble
310         """
311
312 class YoutubeDLHandler(urllib2.HTTPHandler):
313         """Handler for HTTP requests and responses.
314
315         This class, when installed with an OpenerDirector, automatically adds
316         the standard headers to every HTTP request and handles gzipped and
317         deflated responses from web servers. If compression is to be avoided in
318         a particular request, the original request in the program code only has
319         to include the HTTP header "Youtubedl-No-Compression", which will be
320         removed before making the real request.
321
322         Part of this code was copied from:
323
324         http://techknack.net/python-urllib2-handlers/
325
326         Andrew Rowls, the author of that code, agreed to release it to the
327         public domain.
328         """
329
330         @staticmethod
331         def deflate(data):
332                 try:
333                         return zlib.decompress(data, -zlib.MAX_WBITS)
334                 except zlib.error:
335                         return zlib.decompress(data)
336
337         @staticmethod
338         def addinfourl_wrapper(stream, headers, url, code):
339                 if hasattr(urllib2.addinfourl, 'getcode'):
340                         return urllib2.addinfourl(stream, headers, url, code)
341                 ret = urllib2.addinfourl(stream, headers, url)
342                 ret.code = code
343                 return ret
344
345         def http_request(self, req):
346                 for h in std_headers:
347                         if h in req.headers:
348                                 del req.headers[h]
349                         req.add_header(h, std_headers[h])
350                 if 'Youtubedl-no-compression' in req.headers:
351                         if 'Accept-encoding' in req.headers:
352                                 del req.headers['Accept-encoding']
353                         del req.headers['Youtubedl-no-compression']
354                 return req
355
356         def http_response(self, req, resp):
357                 old_resp = resp
358                 # gzip
359                 if resp.headers.get('Content-encoding', '') == 'gzip':
360                         gz = gzip.GzipFile(fileobj=StringIO.StringIO(resp.read()), mode='r')
361                         resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
362                         resp.msg = old_resp.msg
363                 # deflate
364                 if resp.headers.get('Content-encoding', '') == 'deflate':
365                         gz = StringIO.StringIO(self.deflate(resp.read()))
366                         resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
367                         resp.msg = old_resp.msg
368                 return resp