youtube_dl/utils.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 import datetime
   5 import email.utils
   6 import errno
   7 import gzip
   8 import io
   9 import json
  10 import locale
  11 import math
  12 import os
  13 import pipes
  14 import platform
  15 import re
  16 import ssl
  17 import socket
  18 import sys
  19 import traceback
  20 import zlib
  21
  22 try:
  23     import urllib.request as compat_urllib_request
  24 except ImportError: # Python 2
  25     import urllib2 as compat_urllib_request
  26
  27 try:
  28     import urllib.error as compat_urllib_error
  29 except ImportError: # Python 2
  30     import urllib2 as compat_urllib_error
  31
  32 try:
  33     import urllib.parse as compat_urllib_parse
  34 except ImportError: # Python 2
  35     import urllib as compat_urllib_parse
  36
  37 try:
  38     from urllib.parse import urlparse as compat_urllib_parse_urlparse
  39 except ImportError: # Python 2
  40     from urlparse import urlparse as compat_urllib_parse_urlparse
  41
  42 try:
  43     import urllib.parse as compat_urlparse
  44 except ImportError: # Python 2
  45     import urlparse as compat_urlparse
  46
  47 try:
  48     import http.cookiejar as compat_cookiejar
  49 except ImportError: # Python 2
  50     import cookielib as compat_cookiejar
  51
  52 try:
  53     import html.entities as compat_html_entities
  54 except ImportError: # Python 2
  55     import htmlentitydefs as compat_html_entities
  56
  57 try:
  58     import html.parser as compat_html_parser
  59 except ImportError: # Python 2
  60     import HTMLParser as compat_html_parser
  61
  62 try:
  63     import http.client as compat_http_client
  64 except ImportError: # Python 2
  65     import httplib as compat_http_client
  66
  67 try:
  68     from urllib.error import HTTPError as compat_HTTPError
  69 except ImportError:  # Python 2
  70     from urllib2 import HTTPError as compat_HTTPError
  71
  72 try:
  73     from urllib.request import urlretrieve as compat_urlretrieve
  74 except ImportError:  # Python 2
  75     from urllib import urlretrieve as compat_urlretrieve
  76
  77
  78 try:
  79     from subprocess import DEVNULL
  80     compat_subprocess_get_DEVNULL = lambda: DEVNULL
  81 except ImportError:
  82     compat_subprocess_get_DEVNULL = lambda: open(os.path.devnull, 'w')
  83
  84 try:
  85     from urllib.parse import parse_qs as compat_parse_qs
  86 except ImportError: # Python 2
  87     # HACK: The following is the correct parse_qs implementation from cpython 3's stdlib.
  88     # Python 2's version is apparently totally broken
  89     def _unquote(string, encoding='utf-8', errors='replace'):
  90         if string == '':
  91             return string
  92         res = string.split('%')
  93         if len(res) == 1:
  94             return string
  95         if encoding is None:
  96             encoding = 'utf-8'
  97         if errors is None:
  98             errors = 'replace'
  99         # pct_sequence: contiguous sequence of percent-encoded bytes, decoded
 100         pct_sequence = b''
 101         string = res[0]
 102         for item in res[1:]:
 103             try:
 104                 if not item:
 105                     raise ValueError
 106                 pct_sequence += item[:2].decode('hex')
 107                 rest = item[2:]
 108                 if not rest:
 109                     # This segment was just a single percent-encoded character.
 110                     # May be part of a sequence of code units, so delay decoding.
 111                     # (Stored in pct_sequence).
 112                     continue
 113             except ValueError:
 114                 rest = '%' + item
 115             # Encountered non-percent-encoded characters. Flush the current
 116             # pct_sequence.
 117             string += pct_sequence.decode(encoding, errors) + rest
 118             pct_sequence = b''
 119         if pct_sequence:
 120             # Flush the final pct_sequence
 121             string += pct_sequence.decode(encoding, errors)
 122         return string
 123
 124     def _parse_qsl(qs, keep_blank_values=False, strict_parsing=False,
 125                 encoding='utf-8', errors='replace'):
 126         qs, _coerce_result = qs, unicode
 127         pairs = [s2 for s1 in qs.split('&') for s2 in s1.split(';')]
 128         r = []
 129         for name_value in pairs:
 130             if not name_value and not strict_parsing:
 131                 continue
 132             nv = name_value.split('=', 1)
 133             if len(nv) != 2:
 134                 if strict_parsing:
 135                     raise ValueError("bad query field: %r" % (name_value,))
 136                 # Handle case of a control-name with no equal sign
 137                 if keep_blank_values:
 138                     nv.append('')
 139                 else:
 140                     continue
 141             if len(nv[1]) or keep_blank_values:
 142                 name = nv[0].replace('+', ' ')
 143                 name = _unquote(name, encoding=encoding, errors=errors)
 144                 name = _coerce_result(name)
 145                 value = nv[1].replace('+', ' ')
 146                 value = _unquote(value, encoding=encoding, errors=errors)
 147                 value = _coerce_result(value)
 148                 r.append((name, value))
 149         return r
 150
 151     def compat_parse_qs(qs, keep_blank_values=False, strict_parsing=False,
 152                 encoding='utf-8', errors='replace'):
 153         parsed_result = {}
 154         pairs = _parse_qsl(qs, keep_blank_values, strict_parsing,
 155                         encoding=encoding, errors=errors)
 156         for name, value in pairs:
 157             if name in parsed_result:
 158                 parsed_result[name].append(value)
 159             else:
 160                 parsed_result[name] = [value]
 161         return parsed_result
 162
 163 try:
 164     compat_str = unicode # Python 2
 165 except NameError:
 166     compat_str = str
 167
 168 try:
 169     compat_chr = unichr # Python 2
 170 except NameError:
 171     compat_chr = chr
 172
 173 def compat_ord(c):
 174     if type(c) is int: return c
 175     else: return ord(c)
 176
 177 # This is not clearly defined otherwise
 178 compiled_regex_type = type(re.compile(''))
 179
 180 std_headers = {
 181     'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20100101 Firefox/10.0 (Chrome)',
 182     'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
 183     'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
 184     'Accept-Encoding': 'gzip, deflate',
 185     'Accept-Language': 'en-us,en;q=0.5',
 186 }
 187
 188 def preferredencoding():
 189     """Get preferred encoding.
 190
 191     Returns the best encoding scheme for the system, based on
 192     locale.getpreferredencoding() and some further tweaks.
 193     """
 194     try:
 195         pref = locale.getpreferredencoding()
 196         u'TEST'.encode(pref)
 197     except:
 198         pref = 'UTF-8'
 199
 200     return pref
 201
 202 if sys.version_info < (3,0):
 203     def compat_print(s):
 204         print(s.encode(preferredencoding(), 'xmlcharrefreplace'))
 205 else:
 206     def compat_print(s):
 207         assert type(s) == type(u'')
 208         print(s)
 209
 210 # In Python 2.x, json.dump expects a bytestream.
 211 # In Python 3.x, it writes to a character stream
 212 if sys.version_info < (3,0):
 213     def write_json_file(obj, fn):
 214         with open(fn, 'wb') as f:
 215             json.dump(obj, f)
 216 else:
 217     def write_json_file(obj, fn):
 218         with open(fn, 'w', encoding='utf-8') as f:
 219             json.dump(obj, f)
 220
 221 if sys.version_info >= (2,7):
 222     def find_xpath_attr(node, xpath, key, val):
 223         """ Find the xpath xpath[@key=val] """
 224         assert re.match(r'^[a-zA-Z]+$', key)
 225         assert re.match(r'^[a-zA-Z0-9@\s]*$', val)
 226         expr = xpath + u"[@%s='%s']" % (key, val)
 227         return node.find(expr)
 228 else:
 229     def find_xpath_attr(node, xpath, key, val):
 230         for f in node.findall(xpath):
 231             if f.attrib.get(key) == val:
 232                 return f
 233         return None
 234
 235 # On python2.6 the xml.etree.ElementTree.Element methods don't support
 236 # the namespace parameter
 237 def xpath_with_ns(path, ns_map):
 238     components = [c.split(':') for c in path.split('/')]
 239     replaced = []
 240     for c in components:
 241         if len(c) == 1:
 242             replaced.append(c[0])
 243         else:
 244             ns, tag = c
 245             replaced.append('{%s}%s' % (ns_map[ns], tag))
 246     return '/'.join(replaced)
 247
 248 def htmlentity_transform(matchobj):
 249     """Transforms an HTML entity to a character.
 250
 251     This function receives a match object and is intended to be used with
 252     the re.sub() function.
 253     """
 254     entity = matchobj.group(1)
 255
 256     # Known non-numeric HTML entity
 257     if entity in compat_html_entities.name2codepoint:
 258         return compat_chr(compat_html_entities.name2codepoint[entity])
 259
 260     mobj = re.match(u'(?u)#(x?\\d+)', entity)
 261     if mobj is not None:
 262         numstr = mobj.group(1)
 263         if numstr.startswith(u'x'):
 264             base = 16
 265             numstr = u'0%s' % numstr
 266         else:
 267             base = 10
 268         return compat_chr(int(numstr, base))
 269
 270     # Unknown entity in name, return its literal representation
 271     return (u'&%s;' % entity)
 272
 273 compat_html_parser.locatestarttagend = re.compile(r"""<[a-zA-Z][-.a-zA-Z0-9:_]*(?:\s+(?:(?<=['"\s])[^\s/>][^\s/=>]*(?:\s*=+\s*(?:'[^']*'|"[^"]*"|(?!['"])[^>\s]*))?\s*)*)?\s*""", re.VERBOSE) # backport bugfix
 274 class BaseHTMLParser(compat_html_parser.HTMLParser):
 275     def __init(self):
 276         compat_html_parser.HTMLParser.__init__(self)
 277         self.html = None
 278
 279     def loads(self, html):
 280         self.html = html
 281         self.feed(html)
 282         self.close()
 283
 284 class AttrParser(BaseHTMLParser):
 285     """Modified HTMLParser that isolates a tag with the specified attribute"""
 286     def __init__(self, attribute, value):
 287         self.attribute = attribute
 288         self.value = value
 289         self.result = None
 290         self.started = False
 291         self.depth = {}
 292         self.watch_startpos = False
 293         self.error_count = 0
 294         BaseHTMLParser.__init__(self)
 295
 296     def error(self, message):
 297         if self.error_count > 10 or self.started:
 298             raise compat_html_parser.HTMLParseError(message, self.getpos())
 299         self.rawdata = '\n'.join(self.html.split('\n')[self.getpos()[0]:]) # skip one line
 300         self.error_count += 1
 301         self.goahead(1)
 302
 303     def handle_starttag(self, tag, attrs):
 304         attrs = dict(attrs)
 305         if self.started:
 306             self.find_startpos(None)
 307         if self.attribute in attrs and attrs[self.attribute] == self.value:
 308             self.result = [tag]
 309             self.started = True
 310             self.watch_startpos = True
 311         if self.started:
 312             if not tag in self.depth: self.depth[tag] = 0
 313             self.depth[tag] += 1
 314
 315     def handle_endtag(self, tag):
 316         if self.started:
 317             if tag in self.depth: self.depth[tag] -= 1
 318             if self.depth[self.result[0]] == 0:
 319                 self.started = False
 320                 self.result.append(self.getpos())
 321
 322     def find_startpos(self, x):
 323         """Needed to put the start position of the result (self.result[1])
 324         after the opening tag with the requested id"""
 325         if self.watch_startpos:
 326             self.watch_startpos = False
 327             self.result.append(self.getpos())
 328     handle_entityref = handle_charref = handle_data = handle_comment = \
 329     handle_decl = handle_pi = unknown_decl = find_startpos
 330
 331     def get_result(self):
 332         if self.result is None:
 333             return None
 334         if len(self.result) != 3:
 335             return None
 336         lines = self.html.split('\n')
 337         lines = lines[self.result[1][0]-1:self.result[2][0]]
 338         lines[0] = lines[0][self.result[1][1]:]
 339         if len(lines) == 1:
 340             lines[-1] = lines[-1][:self.result[2][1]-self.result[1][1]]
 341         lines[-1] = lines[-1][:self.result[2][1]]
 342         return '\n'.join(lines).strip()
 343 # Hack for https://github.com/rg3/youtube-dl/issues/662
 344 if sys.version_info < (2, 7, 3):
 345     AttrParser.parse_endtag = (lambda self, i:
 346         i + len("</scr'+'ipt>")
 347         if self.rawdata[i:].startswith("</scr'+'ipt>")
 348         else compat_html_parser.HTMLParser.parse_endtag(self, i))
 349
 350 def get_element_by_id(id, html):
 351     """Return the content of the tag with the specified ID in the passed HTML document"""
 352     return get_element_by_attribute("id", id, html)
 353
 354 def get_element_by_attribute(attribute, value, html):
 355     """Return the content of the tag with the specified attribute in the passed HTML document"""
 356     parser = AttrParser(attribute, value)
 357     try:
 358         parser.loads(html)
 359     except compat_html_parser.HTMLParseError:
 360         pass
 361     return parser.get_result()
 362
 363 class MetaParser(BaseHTMLParser):
 364     """
 365     Modified HTMLParser that isolates a meta tag with the specified name
 366     attribute.
 367     """
 368     def __init__(self, name):
 369         BaseHTMLParser.__init__(self)
 370         self.name = name
 371         self.content = None
 372         self.result = None
 373
 374     def handle_starttag(self, tag, attrs):
 375         if tag != 'meta':
 376             return
 377         attrs = dict(attrs)
 378         if attrs.get('name') == self.name:
 379             self.result = attrs.get('content')
 380
 381     def get_result(self):
 382         return self.result
 383
 384 def get_meta_content(name, html):
 385     """
 386     Return the content attribute from the meta tag with the given name attribute.
 387     """
 388     parser = MetaParser(name)
 389     try:
 390         parser.loads(html)
 391     except compat_html_parser.HTMLParseError:
 392         pass
 393     return parser.get_result()
 394
 395
 396 def clean_html(html):
 397     """Clean an HTML snippet into a readable string"""
 398     # Newline vs <br />
 399     html = html.replace('\n', ' ')
 400     html = re.sub(r'\s*<\s*br\s*/?\s*>\s*', '\n', html)
 401     html = re.sub(r'<\s*/\s*p\s*>\s*<\s*p[^>]*>', '\n', html)
 402     # Strip html tags
 403     html = re.sub('<.*?>', '', html)
 404     # Replace html entities
 405     html = unescapeHTML(html)
 406     return html.strip()
 407
 408
 409 def sanitize_open(filename, open_mode):
 410     """Try to open the given filename, and slightly tweak it if this fails.
 411
 412     Attempts to open the given filename. If this fails, it tries to change
 413     the filename slightly, step by step, until it's either able to open it
 414     or it fails and raises a final exception, like the standard open()
 415     function.
 416
 417     It returns the tuple (stream, definitive_file_name).
 418     """
 419     try:
 420         if filename == u'-':
 421             if sys.platform == 'win32':
 422                 import msvcrt
 423                 msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
 424             return (sys.stdout.buffer if hasattr(sys.stdout, 'buffer') else sys.stdout, filename)
 425         stream = open(encodeFilename(filename), open_mode)
 426         return (stream, filename)
 427     except (IOError, OSError) as err:
 428         if err.errno in (errno.EACCES,):
 429             raise
 430
 431         # In case of error, try to remove win32 forbidden chars
 432         alt_filename = os.path.join(
 433                         re.sub(u'[/<>:"\\|\\\\?\\*]', u'#', path_part)
 434                         for path_part in os.path.split(filename)
 435                        )
 436         if alt_filename == filename:
 437             raise
 438         else:
 439             # An exception here should be caught in the caller
 440             stream = open(encodeFilename(filename), open_mode)
 441             return (stream, alt_filename)
 442
 443
 444 def timeconvert(timestr):
 445     """Convert RFC 2822 defined time string into system timestamp"""
 446     timestamp = None
 447     timetuple = email.utils.parsedate_tz(timestr)
 448     if timetuple is not None:
 449         timestamp = email.utils.mktime_tz(timetuple)
 450     return timestamp
 451
 452 def sanitize_filename(s, restricted=False, is_id=False):
 453     """Sanitizes a string so it could be used as part of a filename.
 454     If restricted is set, use a stricter subset of allowed characters.
 455     Set is_id if this is not an arbitrary string, but an ID that should be kept if possible
 456     """
 457     def replace_insane(char):
 458         if char == '?' or ord(char) < 32 or ord(char) == 127:
 459             return ''
 460         elif char == '"':
 461             return '' if restricted else '\''
 462         elif char == ':':
 463             return '_-' if restricted else ' -'
 464         elif char in '\\/|*<>':
 465             return '_'
 466         if restricted and (char in '!&\'()[]{}$;`^,#' or char.isspace()):
 467             return '_'
 468         if restricted and ord(char) > 127:
 469             return '_'
 470         return char
 471
 472     result = u''.join(map(replace_insane, s))
 473     if not is_id:
 474         while '__' in result:
 475             result = result.replace('__', '_')
 476         result = result.strip('_')
 477         # Common case of "Foreign band name - English song title"
 478         if restricted and result.startswith('-_'):
 479             result = result[2:]
 480         if not result:
 481             result = '_'
 482     return result
 483
 484 def orderedSet(iterable):
 485     """ Remove all duplicates from the input iterable """
 486     res = []
 487     for el in iterable:
 488         if el not in res:
 489             res.append(el)
 490     return res
 491
 492 def unescapeHTML(s):
 493     """
 494     @param s a string
 495     """
 496     assert type(s) == type(u'')
 497
 498     result = re.sub(u'(?u)&(.+?);', htmlentity_transform, s)
 499     return result
 500
 501 def encodeFilename(s):
 502     """
 503     @param s The name of the file
 504     """
 505
 506     assert type(s) == type(u'')
 507
 508     # Python 3 has a Unicode API
 509     if sys.version_info >= (3, 0):
 510         return s
 511
 512     if sys.platform == 'win32' and sys.getwindowsversion()[0] >= 5:
 513         # Pass u'' directly to use Unicode APIs on Windows 2000 and up
 514         # (Detecting Windows NT 4 is tricky because 'major >= 4' would
 515         # match Windows 9x series as well. Besides, NT 4 is obsolete.)
 516         return s
 517     else:
 518         encoding = sys.getfilesystemencoding()
 519         if encoding is None:
 520             encoding = 'utf-8'
 521         return s.encode(encoding, 'ignore')
 522
 523 def decodeOption(optval):
 524     if optval is None:
 525         return optval
 526     if isinstance(optval, bytes):
 527         optval = optval.decode(preferredencoding())
 528
 529     assert isinstance(optval, compat_str)
 530     return optval
 531
 532 def formatSeconds(secs):
 533     if secs > 3600:
 534         return '%d:%02d:%02d' % (secs // 3600, (secs % 3600) // 60, secs % 60)
 535     elif secs > 60:
 536         return '%d:%02d' % (secs // 60, secs % 60)
 537     else:
 538         return '%d' % secs
 539
 540 def make_HTTPS_handler(opts_no_check_certificate):
 541     if sys.version_info < (3, 2):
 542         import httplib
 543
 544         class HTTPSConnectionV3(httplib.HTTPSConnection):
 545             def __init__(self, *args, **kwargs):
 546                 httplib.HTTPSConnection.__init__(self, *args, **kwargs)
 547
 548             def connect(self):
 549                 sock = socket.create_connection((self.host, self.port), self.timeout)
 550                 if self._tunnel_host:
 551                     self.sock = sock
 552                     self._tunnel()
 553                 try:
 554                     self.sock = ssl.wrap_socket(sock, self.key_file, self.cert_file, ssl_version=ssl.PROTOCOL_SSLv3)
 555                 except ssl.SSLError:
 556                     self.sock = ssl.wrap_socket(sock, self.key_file, self.cert_file, ssl_version=ssl.PROTOCOL_SSLv23)
 557
 558         class HTTPSHandlerV3(compat_urllib_request.HTTPSHandler):
 559             def https_open(self, req):
 560                 return self.do_open(HTTPSConnectionV3, req)
 561         return HTTPSHandlerV3()
 562     else:
 563         context = ssl.SSLContext(ssl.PROTOCOL_SSLv3)
 564         context.set_default_verify_paths()
 565
 566         context.verify_mode = (ssl.CERT_NONE
 567                                if opts_no_check_certificate
 568                                else ssl.CERT_REQUIRED)
 569         return compat_urllib_request.HTTPSHandler(context=context)
 570
 571 class ExtractorError(Exception):
 572     """Error during info extraction."""
 573     def __init__(self, msg, tb=None, expected=False, cause=None):
 574         """ tb, if given, is the original traceback (so that it can be printed out).
 575         If expected is set, this is a normal error message and most likely not a bug in youtube-dl.
 576         """
 577
 578         if sys.exc_info()[0] in (compat_urllib_error.URLError, socket.timeout, UnavailableVideoError):
 579             expected = True
 580         if not expected:
 581             msg = msg + u'; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type  youtube-dl -U  to update.'
 582         super(ExtractorError, self).__init__(msg)
 583
 584         self.traceback = tb
 585         self.exc_info = sys.exc_info()  # preserve original exception
 586         self.cause = cause
 587
 588     def format_traceback(self):
 589         if self.traceback is None:
 590             return None
 591         return u''.join(traceback.format_tb(self.traceback))
 592
 593
 594 class RegexNotFoundError(ExtractorError):
 595     """Error when a regex didn't match"""
 596     pass
 597
 598
 599 class DownloadError(Exception):
 600     """Download Error exception.
 601
 602     This exception may be thrown by FileDownloader objects if they are not
 603     configured to continue on errors. They will contain the appropriate
 604     error message.
 605     """
 606     def __init__(self, msg, exc_info=None):
 607         """ exc_info, if given, is the original exception that caused the trouble (as returned by sys.exc_info()). """
 608         super(DownloadError, self).__init__(msg)
 609         self.exc_info = exc_info
 610
 611
 612 class SameFileError(Exception):
 613     """Same File exception.
 614
 615     This exception will be thrown by FileDownloader objects if they detect
 616     multiple files would have to be downloaded to the same file on disk.
 617     """
 618     pass
 619
 620
 621 class PostProcessingError(Exception):
 622     """Post Processing exception.
 623
 624     This exception may be raised by PostProcessor's .run() method to
 625     indicate an error in the postprocessing task.
 626     """
 627     def __init__(self, msg):
 628         self.msg = msg
 629
 630 class MaxDownloadsReached(Exception):
 631     """ --max-downloads limit has been reached. """
 632     pass
 633
 634
 635 class UnavailableVideoError(Exception):
 636     """Unavailable Format exception.
 637
 638     This exception will be thrown when a video is requested
 639     in a format that is not available for that video.
 640     """
 641     pass
 642
 643
 644 class ContentTooShortError(Exception):
 645     """Content Too Short exception.
 646
 647     This exception may be raised by FileDownloader objects when a file they
 648     download is too small for what the server announced first, indicating
 649     the connection was probably interrupted.
 650     """
 651     # Both in bytes
 652     downloaded = None
 653     expected = None
 654
 655     def __init__(self, downloaded, expected):
 656         self.downloaded = downloaded
 657         self.expected = expected
 658
 659 class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
 660     """Handler for HTTP requests and responses.
 661
 662     This class, when installed with an OpenerDirector, automatically adds
 663     the standard headers to every HTTP request and handles gzipped and
 664     deflated responses from web servers. If compression is to be avoided in
 665     a particular request, the original request in the program code only has
 666     to include the HTTP header "Youtubedl-No-Compression", which will be
 667     removed before making the real request.
 668
 669     Part of this code was copied from:
 670
 671     http://techknack.net/python-urllib2-handlers/
 672
 673     Andrew Rowls, the author of that code, agreed to release it to the
 674     public domain.
 675     """
 676
 677     @staticmethod
 678     def deflate(data):
 679         try:
 680             return zlib.decompress(data, -zlib.MAX_WBITS)
 681         except zlib.error:
 682             return zlib.decompress(data)
 683
 684     @staticmethod
 685     def addinfourl_wrapper(stream, headers, url, code):
 686         if hasattr(compat_urllib_request.addinfourl, 'getcode'):
 687             return compat_urllib_request.addinfourl(stream, headers, url, code)
 688         ret = compat_urllib_request.addinfourl(stream, headers, url)
 689         ret.code = code
 690         return ret
 691
 692     def http_request(self, req):
 693         for h,v in std_headers.items():
 694             if h in req.headers:
 695                 del req.headers[h]
 696             req.add_header(h, v)
 697         if 'Youtubedl-no-compression' in req.headers:
 698             if 'Accept-encoding' in req.headers:
 699                 del req.headers['Accept-encoding']
 700             del req.headers['Youtubedl-no-compression']
 701         if 'Youtubedl-user-agent' in req.headers:
 702             if 'User-agent' in req.headers:
 703                 del req.headers['User-agent']
 704             req.headers['User-agent'] = req.headers['Youtubedl-user-agent']
 705             del req.headers['Youtubedl-user-agent']
 706         return req
 707
 708     def http_response(self, req, resp):
 709         old_resp = resp
 710         # gzip
 711         if resp.headers.get('Content-encoding', '') == 'gzip':
 712             content = resp.read()
 713             gz = gzip.GzipFile(fileobj=io.BytesIO(content), mode='rb')
 714             try:
 715                 uncompressed = io.BytesIO(gz.read())
 716             except IOError as original_ioerror:
 717                 # There may be junk add the end of the file
 718                 # See http://stackoverflow.com/q/4928560/35070 for details
 719                 for i in range(1, 1024):
 720                     try:
 721                         gz = gzip.GzipFile(fileobj=io.BytesIO(content[:-i]), mode='rb')
 722                         uncompressed = io.BytesIO(gz.read())
 723                     except IOError:
 724                         continue
 725                     break
 726                 else:
 727                     raise original_ioerror
 728             resp = self.addinfourl_wrapper(uncompressed, old_resp.headers, old_resp.url, old_resp.code)
 729             resp.msg = old_resp.msg
 730         # deflate
 731         if resp.headers.get('Content-encoding', '') == 'deflate':
 732             gz = io.BytesIO(self.deflate(resp.read()))
 733             resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
 734             resp.msg = old_resp.msg
 735         return resp
 736
 737     https_request = http_request
 738     https_response = http_response
 739
 740 def unified_strdate(date_str):
 741     """Return a string with the date in the format YYYYMMDD"""
 742     upload_date = None
 743     #Replace commas
 744     date_str = date_str.replace(',',' ')
 745     # %z (UTC offset) is only supported in python>=3.2
 746     date_str = re.sub(r' (\+|-)[\d]*$', '', date_str)
 747     format_expressions = [
 748         '%d %B %Y',
 749         '%B %d %Y',
 750         '%b %d %Y',
 751         '%Y-%m-%d',
 752         '%d/%m/%Y',
 753         '%Y/%m/%d %H:%M:%S',
 754         '%d.%m.%Y %H:%M',
 755         '%Y-%m-%dT%H:%M:%SZ',
 756         '%Y-%m-%dT%H:%M:%S.%fZ',
 757         '%Y-%m-%dT%H:%M:%S.%f0Z',
 758         '%Y-%m-%dT%H:%M:%S',
 759     ]
 760     for expression in format_expressions:
 761         try:
 762             upload_date = datetime.datetime.strptime(date_str, expression).strftime('%Y%m%d')
 763         except:
 764             pass
 765     return upload_date
 766
 767 def determine_ext(url, default_ext=u'unknown_video'):
 768     guess = url.partition(u'?')[0].rpartition(u'.')[2]
 769     if re.match(r'^[A-Za-z0-9]+$', guess):
 770         return guess
 771     else:
 772         return default_ext
 773
 774 def subtitles_filename(filename, sub_lang, sub_format):
 775     return filename.rsplit('.', 1)[0] + u'.' + sub_lang + u'.' + sub_format
 776
 777 def date_from_str(date_str):
 778     """
 779     Return a datetime object from a string in the format YYYYMMDD or
 780     (now|today)[+-][0-9](day|week|month|year)(s)?"""
 781     today = datetime.date.today()
 782     if date_str == 'now'or date_str == 'today':
 783         return today
 784     match = re.match('(now|today)(?P<sign>[+-])(?P<time>\d+)(?P<unit>day|week|month|year)(s)?', date_str)
 785     if match is not None:
 786         sign = match.group('sign')
 787         time = int(match.group('time'))
 788         if sign == '-':
 789             time = -time
 790         unit = match.group('unit')
 791         #A bad aproximation?
 792         if unit == 'month':
 793             unit = 'day'
 794             time *= 30
 795         elif unit == 'year':
 796             unit = 'day'
 797             time *= 365
 798         unit += 's'
 799         delta = datetime.timedelta(**{unit: time})
 800         return today + delta
 801     return datetime.datetime.strptime(date_str, "%Y%m%d").date()
 802
 803 class DateRange(object):
 804     """Represents a time interval between two dates"""
 805     def __init__(self, start=None, end=None):
 806         """start and end must be strings in the format accepted by date"""
 807         if start is not None:
 808             self.start = date_from_str(start)
 809         else:
 810             self.start = datetime.datetime.min.date()
 811         if end is not None:
 812             self.end = date_from_str(end)
 813         else:
 814             self.end = datetime.datetime.max.date()
 815         if self.start > self.end:
 816             raise ValueError('Date range: "%s" , the start date must be before the end date' % self)
 817     @classmethod
 818     def day(cls, day):
 819         """Returns a range that only contains the given day"""
 820         return cls(day,day)
 821     def __contains__(self, date):
 822         """Check if the date is in the range"""
 823         if not isinstance(date, datetime.date):
 824             date = date_from_str(date)
 825         return self.start <= date <= self.end
 826     def __str__(self):
 827         return '%s - %s' % ( self.start.isoformat(), self.end.isoformat())
 828
 829
 830 def platform_name():
 831     """ Returns the platform name as a compat_str """
 832     res = platform.platform()
 833     if isinstance(res, bytes):
 834         res = res.decode(preferredencoding())
 835
 836     assert isinstance(res, compat_str)
 837     return res
 838
 839
 840 def write_string(s, out=None):
 841     if out is None:
 842         out = sys.stderr
 843     assert type(s) == type(u'')
 844
 845     if ('b' in getattr(out, 'mode', '') or
 846             sys.version_info[0] < 3):  # Python 2 lies about mode of sys.stderr
 847         s = s.encode(preferredencoding(), 'ignore')
 848     out.write(s)
 849     out.flush()
 850
 851
 852 def bytes_to_intlist(bs):
 853     if not bs:
 854         return []
 855     if isinstance(bs[0], int):  # Python 3
 856         return list(bs)
 857     else:
 858         return [ord(c) for c in bs]
 859
 860
 861 def intlist_to_bytes(xs):
 862     if not xs:
 863         return b''
 864     if isinstance(chr(0), bytes):  # Python 2
 865         return ''.join([chr(x) for x in xs])
 866     else:
 867         return bytes(xs)
 868
 869
 870 def get_cachedir(params={}):
 871     cache_root = os.environ.get('XDG_CACHE_HOME',
 872                                 os.path.expanduser('~/.cache'))
 873     return params.get('cachedir', os.path.join(cache_root, 'youtube-dl'))
 874
 875
 876 # Cross-platform file locking
 877 if sys.platform == 'win32':
 878     import ctypes.wintypes
 879     import msvcrt
 880
 881     class OVERLAPPED(ctypes.Structure):
 882         _fields_ = [
 883             ('Internal', ctypes.wintypes.LPVOID),
 884             ('InternalHigh', ctypes.wintypes.LPVOID),
 885             ('Offset', ctypes.wintypes.DWORD),
 886             ('OffsetHigh', ctypes.wintypes.DWORD),
 887             ('hEvent', ctypes.wintypes.HANDLE),
 888         ]
 889
 890     kernel32 = ctypes.windll.kernel32
 891     LockFileEx = kernel32.LockFileEx
 892     LockFileEx.argtypes = [
 893         ctypes.wintypes.HANDLE,     # hFile
 894         ctypes.wintypes.DWORD,      # dwFlags
 895         ctypes.wintypes.DWORD,      # dwReserved
 896         ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
 897         ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
 898         ctypes.POINTER(OVERLAPPED)  # Overlapped
 899     ]
 900     LockFileEx.restype = ctypes.wintypes.BOOL
 901     UnlockFileEx = kernel32.UnlockFileEx
 902     UnlockFileEx.argtypes = [
 903         ctypes.wintypes.HANDLE,     # hFile
 904         ctypes.wintypes.DWORD,      # dwReserved
 905         ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
 906         ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
 907         ctypes.POINTER(OVERLAPPED)  # Overlapped
 908     ]
 909     UnlockFileEx.restype = ctypes.wintypes.BOOL
 910     whole_low = 0xffffffff
 911     whole_high = 0x7fffffff
 912
 913     def _lock_file(f, exclusive):
 914         overlapped = OVERLAPPED()
 915         overlapped.Offset = 0
 916         overlapped.OffsetHigh = 0
 917         overlapped.hEvent = 0
 918         f._lock_file_overlapped_p = ctypes.pointer(overlapped)
 919         handle = msvcrt.get_osfhandle(f.fileno())
 920         if not LockFileEx(handle, 0x2 if exclusive else 0x0, 0,
 921                           whole_low, whole_high, f._lock_file_overlapped_p):
 922             raise OSError('Locking file failed: %r' % ctypes.FormatError())
 923
 924     def _unlock_file(f):
 925         assert f._lock_file_overlapped_p
 926         handle = msvcrt.get_osfhandle(f.fileno())
 927         if not UnlockFileEx(handle, 0,
 928                             whole_low, whole_high, f._lock_file_overlapped_p):
 929             raise OSError('Unlocking file failed: %r' % ctypes.FormatError())
 930
 931 else:
 932     import fcntl
 933
 934     def _lock_file(f, exclusive):
 935         fcntl.lockf(f, fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH)
 936
 937     def _unlock_file(f):
 938         fcntl.lockf(f, fcntl.LOCK_UN)
 939
 940
 941 class locked_file(object):
 942     def __init__(self, filename, mode, encoding=None):
 943         assert mode in ['r', 'a', 'w']
 944         self.f = io.open(filename, mode, encoding=encoding)
 945         self.mode = mode
 946
 947     def __enter__(self):
 948         exclusive = self.mode != 'r'
 949         try:
 950             _lock_file(self.f, exclusive)
 951         except IOError:
 952             self.f.close()
 953             raise
 954         return self
 955
 956     def __exit__(self, etype, value, traceback):
 957         try:
 958             _unlock_file(self.f)
 959         finally:
 960             self.f.close()
 961
 962     def __iter__(self):
 963         return iter(self.f)
 964
 965     def write(self, *args):
 966         return self.f.write(*args)
 967
 968     def read(self, *args):
 969         return self.f.read(*args)
 970
 971
 972 def shell_quote(args):
 973     quoted_args = []
 974     encoding = sys.getfilesystemencoding()
 975     if encoding is None:
 976         encoding = 'utf-8'
 977     for a in args:
 978         if isinstance(a, bytes):
 979             # We may get a filename encoded with 'encodeFilename'
 980             a = a.decode(encoding)
 981         quoted_args.append(pipes.quote(a))
 982     return u' '.join(quoted_args)
 983
 984
 985 def takewhile_inclusive(pred, seq):
 986     """ Like itertools.takewhile, but include the latest evaluated element
 987         (the first element so that Not pred(e)) """
 988     for e in seq:
 989         yield e
 990         if not pred(e):
 991             return
 992
 993
 994 def smuggle_url(url, data):
 995     """ Pass additional data in a URL for internal use. """
 996
 997     sdata = compat_urllib_parse.urlencode(
 998         {u'__youtubedl_smuggle': json.dumps(data)})
 999     return url + u'#' + sdata
1000
1001
1002 def unsmuggle_url(smug_url):
1003     if not '#__youtubedl_smuggle' in smug_url:
1004         return smug_url, None
1005     url, _, sdata = smug_url.rpartition(u'#')
1006     jsond = compat_parse_qs(sdata)[u'__youtubedl_smuggle'][0]
1007     data = json.loads(jsond)
1008     return url, data
1009
1010
1011 def format_bytes(bytes):
1012     if bytes is None:
1013         return u'N/A'
1014     if type(bytes) is str:
1015         bytes = float(bytes)
1016     if bytes == 0.0:
1017         exponent = 0
1018     else:
1019         exponent = int(math.log(bytes, 1024.0))
1020     suffix = [u'B', u'KiB', u'MiB', u'GiB', u'TiB', u'PiB', u'EiB', u'ZiB', u'YiB'][exponent]
1021     converted = float(bytes) / float(1024 ** exponent)
1022     return u'%.2f%s' % (converted, suffix)
1023
1024 def str_to_int(int_str):
1025     int_str = re.sub(r'[,\.]', u'', int_str)
1026     return int(int_str)