Merge remote-tracking branch 'jtwaleson/master'
[youtube-dl] / youtube_dl / extractor / youtube.py
index 08a04737c3497eab4c43786a4f3e7e0a45417131..4ebc7b7129e0a5d2f04a6a3a01f32018df75b502 100644 (file)
@@ -1,7 +1,8 @@
 # coding: utf-8
 
-import errno
-import io
+from __future__ import unicode_literals
+
+
 import itertools
 import json
 import os.path
@@ -21,19 +22,18 @@ from ..utils import (
     compat_str,
 
     clean_html,
-    get_cachedir,
     get_element_by_id,
     get_element_by_attribute,
     ExtractorError,
     int_or_none,
-    PagedList,
+    OnDemandPagedList,
     unescapeHTML,
     unified_strdate,
     orderedSet,
-    write_json_file,
     uppercase_escape,
 )
 
+
 class YoutubeBaseInfoExtractor(InfoExtractor):
     """Provide base functions for Youtube extractors"""
     _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
@@ -47,7 +47,7 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
     def _set_language(self):
         return bool(self._download_webpage(
             self._LANG_URL, None,
-            note=u'Setting language', errnote='unable to set language',
+            note='Setting language', errnote='unable to set language',
             fatal=False))
 
     def _login(self):
@@ -62,56 +62,56 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         # No authentication to be performed
         if username is None:
             if self._LOGIN_REQUIRED:
-                raise ExtractorError(u'No login info available, needed for using %s.' % self.IE_NAME, expected=True)
+                raise ExtractorError('No login info available, needed for using %s.' % self.IE_NAME, expected=True)
             return True
 
         login_page = self._download_webpage(
             self._LOGIN_URL, None,
-            note=u'Downloading login page',
-            errnote=u'unable to fetch login page', fatal=False)
+            note='Downloading login page',
+            errnote='unable to fetch login page', fatal=False)
         if login_page is False:
             return
 
         galx = self._search_regex(r'(?s)<input.+?name="GALX".+?value="(.+?)"',
-                                  login_page, u'Login GALX parameter')
+                                  login_page, 'Login GALX parameter')
 
         # Log in
         login_form_strs = {
-                u'continue': u'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
-                u'Email': username,
-                u'GALX': galx,
-                u'Passwd': password,
-
-                u'PersistentCookie': u'yes',
-                u'_utf8': u'霱',
-                u'bgresponse': u'js_disabled',
-                u'checkConnection': u'',
-                u'checkedDomains': u'youtube',
-                u'dnConn': u'',
-                u'pstMsg': u'0',
-                u'rmShown': u'1',
-                u'secTok': u'',
-                u'signIn': u'Sign in',
-                u'timeStmp': u'',
-                u'service': u'youtube',
-                u'uilel': u'3',
-                u'hl': u'en_US',
+            'continue': 'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
+            'Email': username,
+            'GALX': galx,
+            'Passwd': password,
+
+            'PersistentCookie': 'yes',
+            '_utf8': '霱',
+            'bgresponse': 'js_disabled',
+            'checkConnection': '',
+            'checkedDomains': 'youtube',
+            'dnConn': '',
+            'pstMsg': '0',
+            'rmShown': '1',
+            'secTok': '',
+            'signIn': 'Sign in',
+            'timeStmp': '',
+            'service': 'youtube',
+            'uilel': '3',
+            'hl': 'en_US',
         }
 
         # Convert to UTF-8 *before* urlencode because Python 2.x's urlencode
         # chokes on unicode
-        login_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in login_form_strs.items())
+        login_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k, v in login_form_strs.items())
         login_data = compat_urllib_parse.urlencode(login_form).encode('ascii')
 
         req = compat_urllib_request.Request(self._LOGIN_URL, login_data)
         login_results = self._download_webpage(
             req, None,
-            note=u'Logging in', errnote=u'unable to log in', fatal=False)
+            note='Logging in', errnote='unable to log in', fatal=False)
         if login_results is False:
             return False
 
         if re.search(r'id="errormsg_0_Passwd"', login_results) is not None:
-            raise ExtractorError(u'Please use your account password and a two-factor code instead of an application-specific password.', expected=True)
+            raise ExtractorError('Please use your account password and a two-factor code instead of an application-specific password.', expected=True)
 
         # Two-Factor
         # TODO add SMS and phone call support - these require making a request and then prompting the user
@@ -120,59 +120,59 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
             tfa_code = self._get_tfa_info()
 
             if tfa_code is None:
-                self._downloader.report_warning(u'Two-factor authentication required. Provide it with --twofactor <code>')
-                self._downloader.report_warning(u'(Note that only TOTP (Google Authenticator App) codes work at this time.)')
+                self._downloader.report_warning('Two-factor authentication required. Provide it with --twofactor <code>')
+                self._downloader.report_warning('(Note that only TOTP (Google Authenticator App) codes work at this time.)')
                 return False
 
             # Unlike the first login form, secTok and timeStmp are both required for the TFA form
 
             match = re.search(r'id="secTok"\n\s+value=\'(.+)\'/>', login_results, re.M | re.U)
             if match is None:
-                self._downloader.report_warning(u'Failed to get secTok - did the page structure change?')
+                self._downloader.report_warning('Failed to get secTok - did the page structure change?')
             secTok = match.group(1)
             match = re.search(r'id="timeStmp"\n\s+value=\'(.+)\'/>', login_results, re.M | re.U)
             if match is None:
-                self._downloader.report_warning(u'Failed to get timeStmp - did the page structure change?')
+                self._downloader.report_warning('Failed to get timeStmp - did the page structure change?')
             timeStmp = match.group(1)
 
             tfa_form_strs = {
-                u'continue': u'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
-                u'smsToken': u'',
-                u'smsUserPin': tfa_code,
-                u'smsVerifyPin': u'Verify',
-
-                u'PersistentCookie': u'yes',
-                u'checkConnection': u'',
-                u'checkedDomains': u'youtube',
-                u'pstMsg': u'1',
-                u'secTok': secTok,
-                u'timeStmp': timeStmp,
-                u'service': u'youtube',
-                u'hl': u'en_US',
+                'continue': 'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
+                'smsToken': '',
+                'smsUserPin': tfa_code,
+                'smsVerifyPin': 'Verify',
+
+                'PersistentCookie': 'yes',
+                'checkConnection': '',
+                'checkedDomains': 'youtube',
+                'pstMsg': '1',
+                'secTok': secTok,
+                'timeStmp': timeStmp,
+                'service': 'youtube',
+                'hl': 'en_US',
             }
-            tfa_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in tfa_form_strs.items())
+            tfa_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k, v in tfa_form_strs.items())
             tfa_data = compat_urllib_parse.urlencode(tfa_form).encode('ascii')
 
             tfa_req = compat_urllib_request.Request(self._TWOFACTOR_URL, tfa_data)
             tfa_results = self._download_webpage(
                 tfa_req, None,
-                note=u'Submitting TFA code', errnote=u'unable to submit tfa', fatal=False)
+                note='Submitting TFA code', errnote='unable to submit tfa', fatal=False)
 
             if tfa_results is False:
                 return False
 
             if re.search(r'(?i)<form[^>]* id="gaia_secondfactorform"', tfa_results) is not None:
-                self._downloader.report_warning(u'Two-factor code expired. Please try again, or use a one-use backup code instead.')
+                self._downloader.report_warning('Two-factor code expired. Please try again, or use a one-use backup code instead.')
                 return False
             if re.search(r'(?i)<form[^>]* id="gaia_loginform"', tfa_results) is not None:
-                self._downloader.report_warning(u'unable to log in - did the page structure change?')
+                self._downloader.report_warning('unable to log in - did the page structure change?')
                 return False
             if re.search(r'smsauth-interstitial-reviewsettings', tfa_results) is not None:
-                self._downloader.report_warning(u'Your Google account has a security notice. Please log in on your web browser, resolve the notice, and try again.')
+                self._downloader.report_warning('Your Google account has a security notice. Please log in on your web browser, resolve the notice, and try again.')
                 return False
 
         if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
-            self._downloader.report_warning(u'unable to log in: bad username or password')
+            self._downloader.report_warning('unable to log in: bad username or password')
             return False
         return True
 
@@ -181,29 +181,32 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
             'next_url': '/',
             'action_confirm': 'Confirm',
         }
-        req = compat_urllib_request.Request(self._AGE_URL,
-            compat_urllib_parse.urlencode(age_form).encode('ascii'))
+        req = compat_urllib_request.Request(
+            self._AGE_URL,
+            compat_urllib_parse.urlencode(age_form).encode('ascii')
+        )
 
         self._download_webpage(
             req, None,
-            note=u'Confirming age', errnote=u'Unable to confirm age')
-        return True
+            note='Confirming age', errnote='Unable to confirm age',
+            fatal=False)
 
     def _real_initialize(self):
         if self._downloader is None:
             return
-        if not self._set_language():
-            return
+        if self._get_login_info()[0] is not None:
+            if not self._set_language():
+                return
         if not self._login():
             return
         self._confirm_age()
 
 
 class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
-    IE_DESC = u'YouTube.com'
+    IE_DESC = 'YouTube.com'
     _VALID_URL = r"""(?x)^
                      (
-                         (?:https?://|//)?                                    # http(s):// or protocol-independent URL (optional)
+                         (?:https?://|//)                                    # http(s):// or protocol-independent URL
                          (?:(?:(?:(?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie)?\.com/|
                             (?:www\.)?deturl\.com/www\.youtube\.com/|
                             (?:www\.)?pwnyoutube\.com/|
@@ -212,7 +215,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                             youtube\.googleapis\.com/)                        # the various hostnames, with wildcard subdomains
                          (?:.*?\#/)?                                          # handle anchor (#/) redirect urls
                          (?:                                                  # the various things that can precede the ID:
-                             (?:(?:v|embed|e)/)                               # v/ or embed/ or e/
+                             (?:(?:v|embed|e)/(?!videoseries))                # v/ or embed/ or e/
                              |(?:                                             # or the v= param in all its forms
                                  (?:(?:watch|movie)(?:_popup)?(?:\.php)?/?)?  # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
                                  (?:\?|\#!?)                                  # the params delimiter ? or # or #!
@@ -221,10 +224,11 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                              )
                          ))
                          |youtu\.be/                                          # just youtu.be/xxxx
-                         |https?://(?:www\.)?cleanvideosearch\.com/media/action/yt/watch\?videoId=
+                         |(?:www\.)?cleanvideosearch\.com/media/action/yt/watch\?videoId=
                          )
                      )?                                                       # all until now is optional -> you can pass the naked ID
                      ([0-9A-Za-z_-]{11})                                      # here is it! the YouTube video ID
+                     (?!.*?&list=)                                            # combined list/video URLs are handled by the playlist IE
                      (?(1).+)?                                                # if we found the ID, everything can follow
                      $"""
     _NEXT_URL_RE = r'[\?&]next_url=([^&]+)'
@@ -273,6 +277,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         '138': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '160': {'ext': 'mp4', 'height': 144, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '264': {'ext': 'mp4', 'height': 1440, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '298': {'ext': 'mp4', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '299': {'ext': 'mp4', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '266': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'vcodec': 'h264'},
 
         # Dash mp4 audio
         '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 48, 'preference': -50},
@@ -286,6 +293,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         '170': {'ext': 'webm', 'height': 1080, 'width': 1920, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
         '218': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
         '219': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
+        '278': {'ext': 'webm', 'height': 144, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'container': 'webm', 'vcodec': 'VP9'},
         '242': {'ext': 'webm', 'height': 240, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '243': {'ext': 'webm', 'height': 360, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '244': {'ext': 'webm', 'height': 480, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
@@ -295,132 +303,150 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         '248': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '271': {'ext': 'webm', 'height': 1440, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '272': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '302': {'ext': 'webm', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
+        '303': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
 
         # Dash webm audio
         '171': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'abr': 128, 'preference': -50},
         '172': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'abr': 256, 'preference': -50},
 
+        # Dash webm audio with opus inside
+        '249': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 50, 'preference': -50},
+        '250': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 70, 'preference': -50},
+        '251': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 160, 'preference': -50},
+
         # RTMP (unnamed)
         '_rtmp': {'protocol': 'rtmp'},
     }
 
-    IE_NAME = u'youtube'
+    IE_NAME = 'youtube'
     _TESTS = [
         {
-            u"url":  u"http://www.youtube.com/watch?v=BaW_jenozKc",
-            u"file":  u"BaW_jenozKc.mp4",
-            u"info_dict": {
-                u"title": u"youtube-dl test video \"'/\\ä↭𝕐",
-                u"uploader": u"Philipp Hagemeister",
-                u"uploader_id": u"phihag",
-                u"upload_date": u"20121002",
-                u"description": u"test chars:  \"'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de .",
-                u"categories": [u'Science & Technology'],
+            'url': 'http://www.youtube.com/watch?v=BaW_jenozKc',
+            'info_dict': {
+                'id': 'BaW_jenozKc',
+                'ext': 'mp4',
+                'title': 'youtube-dl test video "\'/\\ä↭𝕐',
+                'uploader': 'Philipp Hagemeister',
+                'uploader_id': 'phihag',
+                'upload_date': '20121002',
+                'description': 'test chars:  "\'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de .',
+                'categories': ['Science & Technology'],
                 'like_count': int,
                 'dislike_count': int,
             }
         },
         {
-            u"url":  u"http://www.youtube.com/watch?v=UxxajLWwzqY",
-            u"file":  u"UxxajLWwzqY.mp4",
-            u"note": u"Test generic use_cipher_signature video (#897)",
-            u"info_dict": {
-                u"upload_date": u"20120506",
-                u"title": u"Icona Pop - I Love It (feat. Charli XCX) [OFFICIAL VIDEO]",
-                u"description": u"md5:fea86fda2d5a5784273df5c7cc994d9f",
-                u"uploader": u"Icona Pop",
-                u"uploader_id": u"IconaPop"
+            'url': 'http://www.youtube.com/watch?v=UxxajLWwzqY',
+            'note': 'Test generic use_cipher_signature video (#897)',
+            'info_dict': {
+                'id': 'UxxajLWwzqY',
+                'ext': 'mp4',
+                'upload_date': '20120506',
+                'title': 'Icona Pop - I Love It (feat. Charli XCX) [OFFICIAL VIDEO]',
+                'description': 'md5:fea86fda2d5a5784273df5c7cc994d9f',
+                'uploader': 'Icona Pop',
+                'uploader_id': 'IconaPop',
             }
         },
         {
-            u"url":  u"https://www.youtube.com/watch?v=07FYdnEawAQ",
-            u"file":  u"07FYdnEawAQ.mp4",
-            u"note": u"Test VEVO video with age protection (#956)",
-            u"info_dict": {
-                u"upload_date": u"20130703",
-                u"title": u"Justin Timberlake - Tunnel Vision (Explicit)",
-                u"description": u"md5:64249768eec3bc4276236606ea996373",
-                u"uploader": u"justintimberlakeVEVO",
-                u"uploader_id": u"justintimberlakeVEVO"
+            'url': 'https://www.youtube.com/watch?v=07FYdnEawAQ',
+            'note': 'Test VEVO video with age protection (#956)',
+            'info_dict': {
+                'id': '07FYdnEawAQ',
+                'ext': 'mp4',
+                'upload_date': '20130703',
+                'title': 'Justin Timberlake - Tunnel Vision (Explicit)',
+                'description': 'md5:64249768eec3bc4276236606ea996373',
+                'uploader': 'justintimberlakeVEVO',
+                'uploader_id': 'justintimberlakeVEVO',
             }
         },
         {
-            u"url":  u"//www.YouTube.com/watch?v=yZIXLfi8CZQ",
-            u"file":  u"yZIXLfi8CZQ.mp4",
-            u"note": u"Embed-only video (#1746)",
-            u"info_dict": {
-                u"upload_date": u"20120608",
-                u"title": u"Principal Sexually Assaults A Teacher - Episode 117 - 8th June 2012",
-                u"description": u"md5:09b78bd971f1e3e289601dfba15ca4f7",
-                u"uploader": u"SET India",
-                u"uploader_id": u"setindia"
+            'url': '//www.YouTube.com/watch?v=yZIXLfi8CZQ',
+            'note': 'Embed-only video (#1746)',
+            'info_dict': {
+                'id': 'yZIXLfi8CZQ',
+                'ext': 'mp4',
+                'upload_date': '20120608',
+                'title': 'Principal Sexually Assaults A Teacher - Episode 117 - 8th June 2012',
+                'description': 'md5:09b78bd971f1e3e289601dfba15ca4f7',
+                'uploader': 'SET India',
+                'uploader_id': 'setindia'
             }
         },
         {
-            u"url": u"http://www.youtube.com/watch?v=a9LDPn-MO4I",
-            u"file": u"a9LDPn-MO4I.m4a",
-            u"note": u"256k DASH audio (format 141) via DASH manifest",
-            u"info_dict": {
-                u"upload_date": "20121002",
-                u"uploader_id": "8KVIDEO",
-                u"description": "No description available.",
-                u"uploader": "8KVIDEO",
-                u"title": "UHDTV TEST 8K VIDEO.mp4"
+            'url': 'http://www.youtube.com/watch?v=a9LDPn-MO4I',
+            'note': '256k DASH audio (format 141) via DASH manifest',
+            'info_dict': {
+                'id': 'a9LDPn-MO4I',
+                'ext': 'm4a',
+                'upload_date': '20121002',
+                'uploader_id': '8KVIDEO',
+                'description': '',
+                'uploader': '8KVIDEO',
+                'title': 'UHDTV TEST 8K VIDEO.mp4'
             },
-            u"params": {
-                u"youtube_include_dash_manifest": True,
-                u"format": "141",
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
             },
         },
         # DASH manifest with encrypted signature
         {
-            u'url': u'https://www.youtube.com/watch?v=IB3lcPjvWLA',
-            u'info_dict': {
-                u'id': u'IB3lcPjvWLA',
-                u'ext': u'm4a',
-                u'title': u'Afrojack - The Spark ft. Spree Wilson',
-                u'description': u'md5:9717375db5a9a3992be4668bbf3bc0a8',
-                u'uploader': u'AfrojackVEVO',
-                u'uploader_id': u'AfrojackVEVO',
-                u'upload_date': u'20131011',
+            'url': 'https://www.youtube.com/watch?v=IB3lcPjvWLA',
+            'info_dict': {
+                'id': 'IB3lcPjvWLA',
+                'ext': 'm4a',
+                'title': 'Afrojack - The Spark ft. Spree Wilson',
+                'description': 'md5:9717375db5a9a3992be4668bbf3bc0a8',
+                'uploader': 'AfrojackVEVO',
+                'uploader_id': 'AfrojackVEVO',
+                'upload_date': '20131011',
             },
-            u"params": {
-                u'youtube_include_dash_manifest': True,
-                u'format': '141',
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
             },
         },
+        # Controversy video
+        {
+            'url': 'https://www.youtube.com/watch?v=T4XJQO3qol8',
+            'info_dict': {
+                'id': 'T4XJQO3qol8',
+                'ext': 'mp4',
+                'upload_date': '20100909',
+                'uploader': 'The Amazing Atheist',
+                'uploader_id': 'TheAmazingAtheist',
+                'title': 'Burning Everyone\'s Koran',
+                'description': 'SUBSCRIBE: http://www.youtube.com/saturninefilms\n\nEven Obama has taken a stand against freedom on this issue: http://www.huffingtonpost.com/2010/09/09/obama-gma-interview-quran_n_710282.html',
+            }
+        }
     ]
 
-
-    @classmethod
-    def suitable(cls, url):
-        """Receives a URL and returns True if suitable for this IE."""
-        if YoutubePlaylistIE.suitable(url): return False
-        return re.match(cls._VALID_URL, url) is not None
-
     def __init__(self, *args, **kwargs):
         super(YoutubeIE, self).__init__(*args, **kwargs)
         self._player_cache = {}
 
     def report_video_info_webpage_download(self, video_id):
         """Report attempt to download video info webpage."""
-        self.to_screen(u'%s: Downloading video info webpage' % video_id)
+        self.to_screen('%s: Downloading video info webpage' % video_id)
 
     def report_information_extraction(self, video_id):
         """Report attempt to extract video information."""
-        self.to_screen(u'%s: Extracting video information' % video_id)
+        self.to_screen('%s: Extracting video information' % video_id)
 
     def report_unavailable_format(self, video_id, format):
         """Report extracted video URL."""
-        self.to_screen(u'%s: Format %s not available' % (video_id, format))
+        self.to_screen('%s: Format %s not available' % (video_id, format))
 
     def report_rtmp_download(self):
         """Indicate the download will use the RTMP protocol."""
-        self.to_screen(u'RTMP download detected')
+        self.to_screen('RTMP download detected')
 
     def _signature_cache_id(self, example_sig):
         """ Return a string representation of a signature """
-        return u'.'.join(compat_str(len(part)) for part in example_sig.split('.'))
+        return '.'.join(compat_str(len(part)) for part in example_sig.split('.'))
 
     def _extract_signature_function(self, video_id, player_url, example_sig):
         id_m = re.match(
@@ -435,68 +461,42 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         func_id = '%s_%s_%s' % (
             player_type, player_id, self._signature_cache_id(example_sig))
         assert os.path.basename(func_id) == func_id
-        cache_dir = get_cachedir(self._downloader.params)
 
-        cache_enabled = cache_dir is not None
-        if cache_enabled:
-            cache_fn = os.path.join(os.path.expanduser(cache_dir),
-                                    u'youtube-sigfuncs',
-                                    func_id + '.json')
-            try:
-                with io.open(cache_fn, 'r', encoding='utf-8') as cachef:
-                    cache_spec = json.load(cachef)
-                return lambda s: u''.join(s[i] for i in cache_spec)
-            except IOError:
-                pass  # No cache available
-            except ValueError:
-                try:
-                    file_size = os.path.getsize(cache_fn)
-                except (OSError, IOError) as oe:
-                    file_size = str(oe)
-                self._downloader.report_warning(
-                    u'Cache %s failed (%s)' % (cache_fn, file_size))
+        cache_spec = self._downloader.cache.load('youtube-sigfuncs', func_id)
+        if cache_spec is not None:
+            return lambda s: ''.join(s[i] for i in cache_spec)
 
         if player_type == 'js':
             code = self._download_webpage(
                 player_url, video_id,
-                note=u'Downloading %s player %s' % (player_type, player_id),
-                errnote=u'Download of %s failed' % player_url)
+                note='Downloading %s player %s' % (player_type, player_id),
+                errnote='Download of %s failed' % player_url)
             res = self._parse_sig_js(code)
         elif player_type == 'swf':
             urlh = self._request_webpage(
                 player_url, video_id,
-                note=u'Downloading %s player %s' % (player_type, player_id),
-                errnote=u'Download of %s failed' % player_url)
+                note='Downloading %s player %s' % (player_type, player_id),
+                errnote='Download of %s failed' % player_url)
             code = urlh.read()
             res = self._parse_sig_swf(code)
         else:
             assert False, 'Invalid player type %r' % player_type
 
-        if cache_enabled:
-            try:
-                test_string = u''.join(map(compat_chr, range(len(example_sig))))
-                cache_res = res(test_string)
-                cache_spec = [ord(c) for c in cache_res]
-                try:
-                    os.makedirs(os.path.dirname(cache_fn))
-                except OSError as ose:
-                    if ose.errno != errno.EEXIST:
-                        raise
-                write_json_file(cache_spec, cache_fn)
-            except Exception:
-                tb = traceback.format_exc()
-                self._downloader.report_warning(
-                    u'Writing cache to %r failed: %s' % (cache_fn, tb))
+        if cache_spec is None:
+            test_string = ''.join(map(compat_chr, range(len(example_sig))))
+            cache_res = res(test_string)
+            cache_spec = [ord(c) for c in cache_res]
 
+        self._downloader.cache.store('youtube-sigfuncs', func_id, cache_spec)
         return res
 
     def _print_sig_code(self, func, example_sig):
         def gen_sig_code(idxs):
             def _genslice(start, end, step):
-                starts = u'' if start == 0 else str(start)
-                ends = (u':%d' % (end+step)) if end + step >= 0 else u':'
-                steps = u'' if step == 1 else (u':%d' % step)
-                return u's[%s%s%s]' % (starts, ends, steps)
+                starts = '' if start == 0 else str(start)
+                ends = (':%d' % (end + step)) if end + step >= 0 else ':'
+                steps = '' if step == 1 else (':%d' % step)
+                return 's[%s%s%s]' % (starts, ends, steps)
 
             step = None
             start = '(Never used)'  # Quelch pyflakes warnings - start will be
@@ -513,26 +513,26 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     start = prev
                     continue
                 else:
-                    yield u's[%d]' % prev
+                    yield 's[%d]' % prev
             if step is None:
-                yield u's[%d]' % i
+                yield 's[%d]' % i
             else:
                 yield _genslice(start, i, step)
 
-        test_string = u''.join(map(compat_chr, range(len(example_sig))))
+        test_string = ''.join(map(compat_chr, range(len(example_sig))))
         cache_res = func(test_string)
         cache_spec = [ord(c) for c in cache_res]
-        expr_code = u' + '.join(gen_sig_code(cache_spec))
+        expr_code = ' + '.join(gen_sig_code(cache_spec))
         signature_id_tuple = '(%s)' % (
             ', '.join(compat_str(len(p)) for p in example_sig.split('.')))
-        code = (u'if tuple(len(p) for p in s.split(\'.\')) == %s:\n'
-                u'    return %s\n') % (signature_id_tuple, expr_code)
-        self.to_screen(u'Extracted signature function:\n' + code)
+        code = ('if tuple(len(p) for p in s.split(\'.\')) == %s:\n'
+                '    return %s\n') % (signature_id_tuple, expr_code)
+        self.to_screen('Extracted signature function:\n' + code)
 
     def _parse_sig_js(self, jscode):
         funcname = self._search_regex(
-            r'signature=([$a-zA-Z]+)', jscode,
-             u'Initial JS player signature function name')
+            r'\.sig\|\|([a-zA-Z0-9]+)\(', jscode,
+            'Initial JS player signature function name')
 
         jsi = JSInterpreter(jscode)
         initial_function = jsi.extract_function(funcname)
@@ -540,19 +540,19 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
     def _parse_sig_swf(self, file_contents):
         swfi = SWFInterpreter(file_contents)
-        TARGET_CLASSNAME = u'SignatureDecipher'
+        TARGET_CLASSNAME = 'SignatureDecipher'
         searched_class = swfi.extract_class(TARGET_CLASSNAME)
-        initial_function = swfi.extract_function(searched_class, u'decipher')
+        initial_function = swfi.extract_function(searched_class, 'decipher')
         return lambda s: initial_function([s])
 
     def _decrypt_signature(self, s, video_id, player_url, age_gate=False):
         """Turn the encrypted s field into a working signature"""
 
         if player_url is None:
-            raise ExtractorError(u'Cannot decrypt signature without player_url')
+            raise ExtractorError('Cannot decrypt signature without player_url')
 
-        if player_url.startswith(u'//'):
-            player_url = u'https:' + player_url
+        if player_url.startswith('//'):
+            player_url = 'https:' + player_url
         try:
             player_id = (player_url, self._signature_cache_id(s))
             if player_id not in self._player_cache:
@@ -567,7 +567,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         except Exception as e:
             tb = traceback.format_exc()
             raise ExtractorError(
-                u'Signature extraction failed: ' + tb, cause=e)
+                'Signature extraction failed: ' + tb, cause=e)
 
     def _get_available_subtitles(self, video_id, webpage):
         try:
@@ -575,7 +575,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 'https://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id,
                 video_id, note=False)
         except ExtractorError as err:
-            self._downloader.report_warning(u'unable to download video subtitles: %s' % compat_str(err))
+            self._downloader.report_warning('unable to download video subtitles: %s' % compat_str(err))
             return {}
         lang_list = re.findall(r'name="([^"]*)"[^>]+lang_code="([\w\-]+)"', sub_list)
 
@@ -590,10 +590,10 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 'fmt': self._downloader.params.get('subtitlesformat', 'srt'),
                 'name': unescapeHTML(l[0]).encode('utf-8'),
             })
-            url = u'https://www.youtube.com/api/timedtext?' + params
+            url = 'https://www.youtube.com/api/timedtext?' + params
             sub_lang_list[lang] = url
         if not sub_lang_list:
-            self._downloader.report_warning(u'video doesn\'t have subtitles')
+            self._downloader.report_warning('video doesn\'t have subtitles')
             return {}
         return sub_lang_list
 
@@ -601,9 +601,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         """We need the webpage for getting the captions url, pass it as an
            argument to speed up the process."""
         sub_format = self._downloader.params.get('subtitlesformat', 'srt')
-        self.to_screen(u'%s: Looking for automatic captions' % video_id)
+        self.to_screen('%s: Looking for automatic captions' % video_id)
         mobj = re.search(r';ytplayer.config = ({.*?});', webpage)
-        err_msg = u'Couldn\'t find automatic captions for %s' % video_id
+        err_msg = 'Couldn\'t find automatic captions for %s' % video_id
         if mobj is None:
             self._downloader.report_warning(err_msg)
             return {}
@@ -621,8 +621,8 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             list_url = caption_url + '&' + list_params
             caption_list = self._download_xml(list_url, video_id)
             original_lang_node = caption_list.find('track')
-            if original_lang_node is None or original_lang_node.attrib.get('kind') != 'asr' :
-                self._downloader.report_warning(u'Video doesn\'t have automatic captions')
+            if original_lang_node is None or original_lang_node.attrib.get('kind') != 'asr':
+                self._downloader.report_warning('Video doesn\'t have automatic captions')
                 return {}
             original_lang = original_lang_node.attrib['lang_code']
 
@@ -648,18 +648,19 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
     def extract_id(cls, url):
         mobj = re.match(cls._VALID_URL, url, re.VERBOSE)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
         video_id = mobj.group(2)
         return video_id
 
     def _extract_from_m3u8(self, manifest_url, video_id):
         url_map = {}
+
         def _get_urls(_manifest):
             lines = _manifest.split('\n')
             urls = filter(lambda l: l and not l.startswith('#'),
-                            lines)
+                          lines)
             return urls
-        manifest = self._download_webpage(manifest_url, video_id, u'Downloading formats manifest')
+        manifest = self._download_webpage(manifest_url, video_id, 'Downloading formats manifest')
         formats_urls = _get_urls(manifest)
         for format_url in formats_urls:
             itag = self._search_regex(r'itag/(\d+?)/', format_url, 'itag')
@@ -668,12 +669,12 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
     def _extract_annotations(self, video_id):
         url = 'https://www.youtube.com/annotations_invideo?features=1&legacy=1&video_id=%s' % video_id
-        return self._download_webpage(url, video_id, note=u'Searching for annotations.', errnote=u'Unable to download video annotations.')
+        return self._download_webpage(url, video_id, note='Searching for annotations.', errnote='Unable to download video annotations.')
 
     def _real_extract(self, url):
         proto = (
-            u'http' if self._downloader.params.get('prefer_insecure', False)
-            else u'https')
+            'http' if self._downloader.params.get('prefer_insecure', False)
+            else 'https')
 
         # Extract original video URL from URL with redirection, like age verification, using next_url parameter
         mobj = re.search(self._NEXT_URL_RE, url)
@@ -682,7 +683,17 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         video_id = self.extract_id(url)
 
         # Get video webpage
-        url = proto + '://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
+        url = proto + '://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1&bpctr=9999999999' % video_id
+        pref_cookies = [
+            c for c in self._downloader.cookiejar
+            if c.domain == '.youtube.com' and c.name == 'PREF']
+        for pc in pref_cookies:
+            if 'hl=' in pc.value:
+                pc.value = re.sub(r'hl=[^&]+', 'hl=en', pc.value)
+            else:
+                if pc.value:
+                    pc.value += '&'
+                pc.value += 'hl=en'
         video_webpage = self._download_webpage(url, video_id)
 
         # Attempt to extract SWF player URL
@@ -695,7 +706,6 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         # Get video info
         self.report_video_info_webpage_download(video_id)
         if re.search(r'player-age-gate-content">', video_webpage) is not None:
-            self.report_age_confirmation()
             age_gate = True
             # We simulate the access to the video from www.youtube.com/v/{video_id}
             # this can be viewed without login into Youtube
@@ -703,32 +713,33 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 'video_id': video_id,
                 'eurl': 'https://youtube.googleapis.com/v/' + video_id,
                 'sts': self._search_regex(
-                    r'"sts"\s*:\s*(\d+)', video_webpage, 'sts'),
+                    r'"sts"\s*:\s*(\d+)', video_webpage, 'sts', default=''),
             })
             video_info_url = proto + '://www.youtube.com/get_video_info?' + data
-            video_info_webpage = self._download_webpage(video_info_url, video_id,
-                                    note=False,
-                                    errnote='unable to download video info webpage')
+            video_info_webpage = self._download_webpage(
+                video_info_url, video_id,
+                note='Refetching age-gated info webpage',
+                errnote='unable to download video info webpage')
             video_info = compat_parse_qs(video_info_webpage)
         else:
             age_gate = False
             for el_type in ['&el=embedded', '&el=detailpage', '&el=vevo', '']:
                 video_info_url = (proto + '://www.youtube.com/get_video_info?&video_id=%s%s&ps=default&eurl=&gl=US&hl=en'
-                        % (video_id, el_type))
+                                  % (video_id, el_type))
                 video_info_webpage = self._download_webpage(video_info_url, video_id,
-                                        note=False,
-                                        errnote='unable to download video info webpage')
+                                                            note=False,
+                                                            errnote='unable to download video info webpage')
                 video_info = compat_parse_qs(video_info_webpage)
                 if 'token' in video_info:
                     break
         if 'token' not in video_info:
             if 'reason' in video_info:
                 raise ExtractorError(
-                    u'YouTube said: %s' % video_info['reason'][0],
+                    'YouTube said: %s' % video_info['reason'][0],
                     expected=True, video_id=video_id)
             else:
                 raise ExtractorError(
-                    u'"token" parameter not in video info for unknown reason',
+                    '"token" parameter not in video info for unknown reason',
                     video_id=video_id)
 
         if 'view_count' in video_info:
@@ -738,14 +749,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
         # Check for "rental" videos
         if 'ypc_video_rental_bar_text' in video_info and 'author' not in video_info:
-            raise ExtractorError(u'"rental" videos not supported')
+            raise ExtractorError('"rental" videos not supported')
 
         # Start extracting information
         self.report_information_extraction(video_id)
 
         # uploader
         if 'author' not in video_info:
-            raise ExtractorError(u'Unable to extract uploader name')
+            raise ExtractorError('Unable to extract uploader name')
         video_uploader = compat_urllib_parse.unquote_plus(video_info['author'][0])
 
         # uploader_id
@@ -754,14 +765,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         if mobj is not None:
             video_uploader_id = mobj.group(1)
         else:
-            self._downloader.report_warning(u'unable to extract uploader nickname')
+            self._downloader.report_warning('unable to extract uploader nickname')
 
         # title
         if 'title' in video_info:
             video_title = video_info['title'][0]
         else:
-            self._downloader.report_warning(u'Unable to extract video title')
-            video_title = u'_'
+            self._downloader.report_warning('Unable to extract video title')
+            video_title = '_'
 
         # thumbnail image
         # We try first to get a high quality image:
@@ -770,7 +781,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         if m_thumb is not None:
             video_thumbnail = m_thumb.group(1)
         elif 'thumbnail_url' not in video_info:
-            self._downloader.report_warning(u'unable to extract video thumbnail')
+            self._downloader.report_warning('unable to extract video thumbnail')
             video_thumbnail = None
         else:   # don't panic if we can't find it
             video_thumbnail = compat_urllib_parse.unquote_plus(video_info['thumbnail_url'][0])
@@ -815,7 +826,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             if fd_mobj:
                 video_description = unescapeHTML(fd_mobj.group(1))
             else:
-                video_description = u''
+                video_description = ''
 
         def _extract_count(count_name):
             count = self._search_regex(
@@ -824,8 +835,8 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             if count is not None:
                 return int(count.replace(',', ''))
             return None
-        like_count = _extract_count(u'like')
-        dislike_count = _extract_count(u'dislike')
+        like_count = _extract_count('like')
+        dislike_count = _extract_count('dislike')
 
         # subtitles
         video_subtitles = self.extract_subtitles(video_id, video_webpage)
@@ -835,7 +846,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             return
 
         if 'length_seconds' not in video_info:
-            self._downloader.report_warning(u'unable to extract video duration')
+            self._downloader.report_warning('unable to extract video duration')
             video_duration = None
         else:
             video_duration = int(compat_urllib_parse.unquote_plus(video_info['length_seconds'][0]))
@@ -843,7 +854,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         # annotations
         video_annotations = None
         if self._downloader.params.get('writeannotations', False):
-                video_annotations = self._extract_annotations(video_id)
+            video_annotations = self._extract_annotations(video_id)
 
         # Decide which formats to download
         try:
@@ -856,13 +867,13 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             # Easy way to know if the 's' value is in url_encoded_fmt_stream_map
             # this signatures are encrypted
             if 'url_encoded_fmt_stream_map' not in args:
-                raise ValueError(u'No stream_map present')  # caught below
+                raise ValueError('No stream_map present')  # caught below
             re_signature = re.compile(r'[&,]s=')
             m_s = re_signature.search(args['url_encoded_fmt_stream_map'])
             if m_s is not None:
-                self.to_screen(u'%s: Encrypted signatures detected.' % video_id)
+                self.to_screen('%s: Encrypted signatures detected.' % video_id)
                 video_info['url_encoded_fmt_stream_map'] = [args['url_encoded_fmt_stream_map']]
-            m_s = re_signature.search(args.get('adaptive_fmts', u''))
+            m_s = re_signature.search(args.get('adaptive_fmts', ''))
             if m_s is not None:
                 if 'adaptive_fmts' in video_info:
                     video_info['adaptive_fmts'][0] += ',' + args['adaptive_fmts']
@@ -893,7 +904,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 'player_url': player_url,
             }]
         elif len(video_info.get('url_encoded_fmt_stream_map', [])) >= 1 or len(video_info.get('adaptive_fmts', [])) >= 1:
-            encoded_url_map = video_info.get('url_encoded_fmt_stream_map', [''])[0] + ',' + video_info.get('adaptive_fmts',[''])[0]
+            encoded_url_map = video_info.get('url_encoded_fmt_stream_map', [''])[0] + ',' + video_info.get('adaptive_fmts', [''])[0]
             if 'rtmpe%3Dyes' in encoded_url_map:
                 raise ExtractorError('rtmpe downloads are not supported, see https://github.com/rg3/youtube-dl/issues/343 for more information.', expected=True)
             url_map = {}
@@ -912,12 +923,12 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     if not age_gate:
                         jsplayer_url_json = self._search_regex(
                             r'"assets":.+?"js":\s*("[^"]+")',
-                            video_webpage, u'JS player URL')
+                            video_webpage, 'JS player URL')
                         player_url = json.loads(jsplayer_url_json)
                     if player_url is None:
                         player_url_json = self._search_regex(
                             r'ytplayer\.config.*?"url"\s*:\s*("[^"]+")',
-                            video_webpage, u'age gate player URL')
+                            video_webpage, 'age gate player URL')
                         player_url = json.loads(player_url_json)
 
                     if self._downloader.params.get('verbose'):
@@ -928,18 +939,18 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                             if player_url.endswith('swf'):
                                 player_version = self._search_regex(
                                     r'-(.+?)(?:/watch_as3)?\.swf$', player_url,
-                                    u'flash player', fatal=False)
+                                    'flash player', fatal=False)
                                 player_desc = 'flash player %s' % player_version
                             else:
                                 player_version = self._search_regex(
                                     r'html5player-([^/]+?)(?:/html5player)?\.js',
                                     player_url,
                                     'html5 player', fatal=False)
-                                player_desc = u'html5 player %s' % player_version
+                                player_desc = 'html5 player %s' % player_version
 
                         parts_sizes = self._signature_cache_id(encrypted_sig)
-                        self.to_screen(u'{%s} signature length %s, %s' %
-                            (format_id, parts_sizes, player_desc))
+                        self.to_screen('{%s} signature length %s, %s' %
+                                       (format_id, parts_sizes, player_desc))
 
                     signature = self._decrypt_signature(
                         encrypted_sig, video_id, player_url, age_gate)
@@ -953,10 +964,10 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             url_map = self._extract_from_m3u8(manifest_url, video_id)
             formats = _map_to_format_list(url_map)
         else:
-            raise ExtractorError(u'no conn, hlsvp or url_encoded_fmt_stream_map information found in video info')
+            raise ExtractorError('no conn, hlsvp or url_encoded_fmt_stream_map information found in video info')
 
         # Look for the DASH manifest
-        if (self._downloader.params.get('youtube_include_dash_manifest', False)):
+        if self._downloader.params.get('youtube_include_dash_manifest', True):
             try:
                 # The DASH manifest used needs to be the one from the original video_webpage.
                 # The one found in get_video_info seems to be using different signatures.
@@ -967,6 +978,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     dash_manifest_url = video_info.get('dashmpd')[0]
                 else:
                     dash_manifest_url = ytplayer_config['args']['dashmpd']
+
                 def decrypt_sig(mobj):
                     s = mobj.group(1)
                     dec_s = self._decrypt_signature(s, video_id, player_url, age_gate)
@@ -974,9 +986,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 dash_manifest_url = re.sub(r'/s/([\w\.]+)', decrypt_sig, dash_manifest_url)
                 dash_doc = self._download_xml(
                     dash_manifest_url, video_id,
-                    note=u'Downloading DASH manifest',
-                    errnote=u'Could not download DASH manifest')
-                for r in dash_doc.findall(u'.//{urn:mpeg:DASH:schema:MPD:2011}Representation'):
+                    note='Downloading DASH manifest',
+                    errnote='Could not download DASH manifest')
+                for r in dash_doc.findall('.//{urn:mpeg:DASH:schema:MPD:2011}Representation'):
                     url_el = r.find('{urn:mpeg:DASH:schema:MPD:2011}BaseURL')
                     if url_el is None:
                         continue
@@ -1002,44 +1014,45 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                         existing_format.update(f)
 
             except (ExtractorError, KeyError) as e:
-                self.report_warning(u'Skipping DASH manifest: %s' % e, video_id)
+                self.report_warning('Skipping DASH manifest: %r' % e, video_id)
 
         self._sort_formats(formats)
 
         return {
-            'id':           video_id,
-            'uploader':     video_uploader,
-            'uploader_id':  video_uploader_id,
-            'upload_date':  upload_date,
-            'title':        video_title,
-            'thumbnail':    video_thumbnail,
-            'description':  video_description,
-            'categories':   video_categories,
-            'subtitles':    video_subtitles,
-            'duration':     video_duration,
-            'age_limit':    18 if age_gate else 0,
-            'annotations':  video_annotations,
+            'id': video_id,
+            'uploader': video_uploader,
+            'uploader_id': video_uploader_id,
+            'upload_date': upload_date,
+            'title': video_title,
+            'thumbnail': video_thumbnail,
+            'description': video_description,
+            'categories': video_categories,
+            'subtitles': video_subtitles,
+            'duration': video_duration,
+            'age_limit': 18 if age_gate else 0,
+            'annotations': video_annotations,
             'webpage_url': proto + '://www.youtube.com/watch?v=%s' % video_id,
-            'view_count':   view_count,
+            'view_count': view_count,
             'like_count': like_count,
             'dislike_count': dislike_count,
-            'formats':      formats,
+            'formats': formats,
         }
 
+
 class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
-    IE_DESC = u'YouTube.com playlists'
+    IE_DESC = 'YouTube.com playlists'
     _VALID_URL = r"""(?x)(?:
                         (?:https?://)?
                         (?:\w+\.)?
                         youtube\.com/
                         (?:
-                           (?:course|view_play_list|my_playlists|artist|playlist|watch)
+                           (?:course|view_play_list|my_playlists|artist|playlist|watch|embed/videoseries)
                            \? (?:.*?&)*? (?:p|a|list)=
                         |  p/
                         )
                         (
                             (?:PL|LL|EC|UU|FL|RD)?[0-9A-Za-z-_]{10,}
-                            # Top tracks, they can also include dots 
+                            # Top tracks, they can also include dots
                             |(?:MC)[\w\.]*
                         )
                         .*
@@ -1049,7 +1062,62 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
     _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s'
     _MORE_PAGES_INDICATOR = r'data-link-type="next"'
     _VIDEO_RE = r'href="\s*/watch\?v=(?P<id>[0-9A-Za-z_-]{11})&amp;[^"]*?index=(?P<index>\d+)'
-    IE_NAME = u'youtube:playlist'
+    IE_NAME = 'youtube:playlist'
+    _TESTS = [{
+        'url': 'https://www.youtube.com/playlist?list=PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re',
+        'info_dict': {
+            'title': 'ytdl test PL',
+            'id': 'PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re',
+        },
+        'playlist_count': 3,
+    }, {
+        'url': 'https://www.youtube.com/playlist?list=PLtPgu7CB4gbZDA7i_euNxn75ISqxwZPYx',
+        'info_dict': {
+            'title': 'YDL_Empty_List',
+        },
+        'playlist_count': 0,
+    }, {
+        'note': 'Playlist with deleted videos (#651). As a bonus, the video #51 is also twice in this list.',
+        'url': 'https://www.youtube.com/playlist?list=PLwP_SiAcdui0KVebT0mU9Apz359a4ubsC',
+        'info_dict': {
+            'title': '29C3: Not my department',
+        },
+        'playlist_count': 95,
+    }, {
+        'note': 'issue #673',
+        'url': 'PLBB231211A4F62143',
+        'info_dict': {
+            'title': '[OLD]Team Fortress 2 (Class-based LP)',
+        },
+        'playlist_mincount': 26,
+    }, {
+        'note': 'Large playlist',
+        'url': 'https://www.youtube.com/playlist?list=UUBABnxM4Ar9ten8Mdjj1j0Q',
+        'info_dict': {
+            'title': 'Uploads from Cauchemar',
+        },
+        'playlist_mincount': 799,
+    }, {
+        'url': 'PLtPgu7CB4gbY9oDN3drwC3cMbJggS7dKl',
+        'info_dict': {
+            'title': 'YDL_safe_search',
+        },
+        'playlist_count': 2,
+    }, {
+        'note': 'embedded',
+        'url': 'http://www.youtube.com/embed/videoseries?list=PL6IaIsEjSbf96XFRuNccS_RuEXwNdsoEu',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA15',
+        }
+    }, {
+        'note': 'Embedded SWF player',
+        'url': 'http://www.youtube.com/p/YN5VISEtHet5D4NEvfTd0zcgFk84NqFZ?hl=en_US&fs=1&rel=0',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA7',
+        }
+    }]
 
     def _real_initialize(self):
         self._login()
@@ -1064,7 +1132,7 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         # the id of the playlist is just 'RD' + video_id
         url = 'https://youtube.com/watch?v=%s&list=%s' % (playlist_id[-11:], playlist_id)
         webpage = self._download_webpage(
-            url, playlist_id, u'Downloading Youtube mix')
+            url, playlist_id, 'Downloading Youtube mix')
         search_title = lambda class_name: get_element_by_attribute('class', class_name, webpage)
         title_span = (
             search_title('playlist-title') or
@@ -1083,7 +1151,7 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         # Extract playlist id
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
         playlist_id = mobj.group(1) or mobj.group(2)
 
         # Check if it's a video-specific URL
@@ -1091,17 +1159,17 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         if 'v' in query_dict:
             video_id = query_dict['v'][0]
             if self._downloader.params.get('noplaylist'):
-                self.to_screen(u'Downloading just video %s because of --no-playlist' % video_id)
+                self.to_screen('Downloading just video %s because of --no-playlist' % video_id)
                 return self.url_result(video_id, 'Youtube', video_id=video_id)
             else:
-                self.to_screen(u'Downloading playlist %s - add --no-playlist to just download video %s' % (playlist_id, video_id))
+                self.to_screen('Downloading playlist %s - add --no-playlist to just download video %s' % (playlist_id, video_id))
 
         if playlist_id.startswith('RD'):
             # Mixes require a custom extraction process
             return self._extract_mix(playlist_id)
         if playlist_id.startswith('TL'):
-            raise ExtractorError(u'For downloading YouTube.com top lists, use '
-                u'the "yttoplist" keyword, for example "youtube-dl \'yttoplist:music:Top Tracks\'"', expected=True)
+            raise ExtractorError('For downloading YouTube.com top lists, use '
+                                 'the "yttoplist" keyword, for example "youtube-dl \'yttoplist:music:Top Tracks\'"', expected=True)
 
         url = self._TEMPLATE_URL % playlist_id
         page = self._download_webpage(url, playlist_id)
@@ -1110,7 +1178,7 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         # Check if the playlist exists or is private
         if re.search(r'<div class="yt-alert-message">[^<]*?(The|This) playlist (does not exist|is private)[^<]*?</div>', page) is not None:
             raise ExtractorError(
-                u'The playlist doesn\'t exist or is private, use --username or '
+                'The playlist doesn\'t exist or is private, use --username or '
                 '--netrc to access it.',
                 expected=True)
 
@@ -1137,34 +1205,44 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
 
         playlist_title = self._html_search_regex(
             r'(?s)<h1 class="pl-header-title[^"]*">\s*(.*?)\s*</h1>',
-            page, u'title')
+            page, 'title')
 
         url_results = self._ids_to_results(ids)
         return self.playlist_result(url_results, playlist_id, playlist_title)
 
 
 class YoutubeTopListIE(YoutubePlaylistIE):
-    IE_NAME = u'youtube:toplist'
-    IE_DESC = (u'YouTube.com top lists, "yttoplist:{channel}:{list title}"'
-        u' (Example: "yttoplist:music:Top Tracks")')
+    IE_NAME = 'youtube:toplist'
+    IE_DESC = ('YouTube.com top lists, "yttoplist:{channel}:{list title}"'
+               ' (Example: "yttoplist:music:Top Tracks")')
     _VALID_URL = r'yttoplist:(?P<chann>.*?):(?P<title>.*?)$'
+    _TESTS = [{
+        'url': 'yttoplist:music:Trending',
+        'playlist_mincount': 5,
+        'skip': 'Only works for logged-in users',
+    }]
 
     def _real_extract(self, url):
         mobj = re.match(self._VALID_URL, url)
         channel = mobj.group('chann')
         title = mobj.group('title')
         query = compat_urllib_parse.urlencode({'title': title})
-        playlist_re = 'href="([^"]+?%s.*?)"' % re.escape(query)
-        channel_page = self._download_webpage('https://www.youtube.com/%s' % channel, title)
-        link = self._html_search_regex(playlist_re, channel_page, u'list')
+        channel_page = self._download_webpage(
+            'https://www.youtube.com/%s' % channel, title)
+        link = self._html_search_regex(
+            r'''(?x)
+                <a\s+href="([^"]+)".*?>\s*
+                <span\s+class="branded-page-module-title-text">\s*
+                <span[^>]*>.*?%s.*?</span>''' % re.escape(query),
+            channel_page, 'list')
         url = compat_urlparse.urljoin('https://www.youtube.com/', link)
-        
+
         video_re = r'data-index="\d+".*?data-video-id="([0-9A-Za-z_-]{11})"'
         ids = []
         # sometimes the webpage doesn't contain the videos
         # retry until we get them
         for i in itertools.count(0):
-            msg = u'Downloading Youtube mix'
+            msg = 'Downloading Youtube mix'
             if i > 0:
                 msg += ', retry #%d' % i
 
@@ -1177,11 +1255,16 @@ class YoutubeTopListIE(YoutubePlaylistIE):
 
 
 class YoutubeChannelIE(InfoExtractor):
-    IE_DESC = u'YouTube.com channels'
+    IE_DESC = 'YouTube.com channels'
     _VALID_URL = r"^(?:https?://)?(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie)?\.com)/channel/([0-9A-Za-z_-]+)"
     _MORE_PAGES_INDICATOR = 'yt-uix-load-more'
     _MORE_PAGES_URL = 'https://www.youtube.com/c4_browse_ajax?action_load_more_videos=1&flow=list&paging=%s&view=0&sort=da&channel_id=%s'
-    IE_NAME = u'youtube:channel'
+    IE_NAME = 'youtube:channel'
+    _TESTS = [{
+        'note': 'paginated channel',
+        'url': 'https://www.youtube.com/channel/UCKfVa3S1e4PHvxWcwyMMg8w',
+        'playlist_mincount': 91,
+    }]
 
     def extract_videos_from_page(self, page):
         ids_in_page = []
@@ -1194,7 +1277,7 @@ class YoutubeChannelIE(InfoExtractor):
         # Extract channel id
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
 
         # Download channel page
         channel_id = mobj.group(1)
@@ -1216,16 +1299,16 @@ class YoutubeChannelIE(InfoExtractor):
             for pagenum in itertools.count(1):
                 url = self._MORE_PAGES_URL % (pagenum, channel_id)
                 page = self._download_json(
-                    url, channel_id, note=u'Downloading page #%s' % pagenum,
+                    url, channel_id, note='Downloading page #%s' % pagenum,
                     transform_source=uppercase_escape)
 
                 ids_in_page = self.extract_videos_from_page(page['content_html'])
                 video_ids.extend(ids_in_page)
-    
+
                 if self._MORE_PAGES_INDICATOR not in page['load_more_widget_html']:
                     break
 
-        self._downloader.to_screen(u'[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
+        self._downloader.to_screen('[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
 
         url_entries = [self.url_result(video_id, 'Youtube', video_id=video_id)
                        for video_id in video_ids]
@@ -1233,26 +1316,39 @@ class YoutubeChannelIE(InfoExtractor):
 
 
 class YoutubeUserIE(InfoExtractor):
-    IE_DESC = u'YouTube.com user videos (URL or "ytuser" keyword)'
+    IE_DESC = 'YouTube.com user videos (URL or "ytuser" keyword)'
     _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/(?:user/)?(?!(?:attribution_link|watch|results)(?:$|[^a-z_A-Z0-9-])))|ytuser:)(?!feed/)([A-Za-z0-9_-]+)'
     _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/users/%s'
     _GDATA_PAGE_SIZE = 50
     _GDATA_URL = 'https://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d&alt=json'
-    IE_NAME = u'youtube:user'
+    IE_NAME = 'youtube:user'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/user/TheLinuxFoundation',
+        'playlist_mincount': 320,
+        'info_dict': {
+            'title': 'TheLinuxFoundation',
+        }
+    }, {
+        'url': 'ytuser:phihag',
+        'only_matching': True,
+    }]
 
     @classmethod
     def suitable(cls, url):
         # Don't return True if the url can be extracted with other youtube
         # extractor, the regex would is too permissive and it would match.
         other_ies = iter(klass for (name, klass) in globals().items() if name.endswith('IE') and klass is not cls)
-        if any(ie.suitable(url) for ie in other_ies): return False
-        else: return super(YoutubeUserIE, cls).suitable(url)
+        if any(ie.suitable(url) for ie in other_ies):
+            return False
+        else:
+            return super(YoutubeUserIE, cls).suitable(url)
 
     def _real_extract(self, url):
         # Extract username
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
 
         username = mobj.group(1)
 
@@ -1267,13 +1363,13 @@ class YoutubeUserIE(InfoExtractor):
             gdata_url = self._GDATA_URL % (username, self._GDATA_PAGE_SIZE, start_index)
             page = self._download_webpage(
                 gdata_url, username,
-                u'Downloading video ids from %d to %d' % (
+                'Downloading video ids from %d to %d' % (
                     start_index, start_index + self._GDATA_PAGE_SIZE))
 
             try:
                 response = json.loads(page)
             except ValueError as err:
-                raise ExtractorError(u'Invalid JSON in API response: ' + compat_str(err))
+                raise ExtractorError('Invalid JSON in API response: ' + compat_str(err))
             if 'entry' not in response['feed']:
                 return
 
@@ -1289,16 +1385,16 @@ class YoutubeUserIE(InfoExtractor):
                     'id': video_id,
                     'title': title,
                 }
-        url_results = PagedList(download_page, self._GDATA_PAGE_SIZE)
+        url_results = OnDemandPagedList(download_page, self._GDATA_PAGE_SIZE)
 
         return self.playlist_result(url_results, playlist_title=username)
 
 
 class YoutubeSearchIE(SearchInfoExtractor):
-    IE_DESC = u'YouTube.com searches'
-    _API_URL = u'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc'
+    IE_DESC = 'YouTube.com searches'
+    _API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc'
     _MAX_RESULTS = 1000
-    IE_NAME = u'youtube:search'
+    IE_NAME = 'youtube:search'
     _SEARCH_KEY = 'ytsearch'
 
     def _get_n_results(self, query, n):
@@ -1314,15 +1410,15 @@ class YoutubeSearchIE(SearchInfoExtractor):
                 compat_urllib_parse.quote_plus(query.encode('utf-8')),
                 (PAGE_SIZE * pagenum) + 1)
             data_json = self._download_webpage(
-                result_url, video_id=u'query "%s"' % query,
-                note=u'Downloading page %s' % (pagenum + 1),
-                errnote=u'Unable to download API page')
+                result_url, video_id='query "%s"' % query,
+                note='Downloading page %s' % (pagenum + 1),
+                errnote='Unable to download API page')
             data = json.loads(data_json)
             api_response = data['data']
 
             if 'items' not in api_response:
                 raise ExtractorError(
-                    u'[youtube] No video results', expected=True)
+                    '[youtube] No video results', expected=True)
 
             new_ids = list(video['id'] for video in api_response['items'])
             video_ids += new_ids
@@ -1341,13 +1437,20 @@ class YoutubeSearchDateIE(YoutubeSearchIE):
     IE_NAME = YoutubeSearchIE.IE_NAME + ':date'
     _API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc&orderby=published'
     _SEARCH_KEY = 'ytsearchdate'
-    IE_DESC = u'YouTube.com searches, newest videos first'
+    IE_DESC = 'YouTube.com searches, newest videos first'
 
 
 class YoutubeSearchURLIE(InfoExtractor):
-    IE_DESC = u'YouTube.com search URLs'
-    IE_NAME = u'youtube:search_url'
+    IE_DESC = 'YouTube.com search URLs'
+    IE_NAME = 'youtube:search_url'
     _VALID_URL = r'https?://(?:www\.)?youtube\.com/results\?(.*?&)?search_query=(?P<query>[^&]+)(?:[&]|$)'
+    _TESTS = [{
+        'url': 'https://www.youtube.com/results?baz=bar&search_query=youtube-dl+test+video&filters=video&lclk=video',
+        'playlist_mincount': 5,
+        'info_dict': {
+            'title': 'youtube-dl test video',
+        }
+    }]
 
     def _real_extract(self, url):
         mobj = re.match(self._VALID_URL, url)
@@ -1355,7 +1458,7 @@ class YoutubeSearchURLIE(InfoExtractor):
 
         webpage = self._download_webpage(url, query)
         result_code = self._search_regex(
-            r'(?s)<ol class="item-section"(.*?)</ol>', webpage, u'result HTML')
+            r'(?s)<ol class="item-section"(.*?)</ol>', webpage, 'result HTML')
 
         part_codes = re.findall(
             r'(?s)<h3 class="yt-lockup-title">(.*?)</h3>', result_code)
@@ -1381,18 +1484,39 @@ class YoutubeSearchURLIE(InfoExtractor):
 
 
 class YoutubeShowIE(InfoExtractor):
-    IE_DESC = u'YouTube.com (multi-season) shows'
-    _VALID_URL = r'https?://www\.youtube\.com/show/(.*)'
-    IE_NAME = u'youtube:show'
+    IE_DESC = 'YouTube.com (multi-season) shows'
+    _VALID_URL = r'https?://www\.youtube\.com/show/(?P<id>[^?#]*)'
+    IE_NAME = 'youtube:show'
+    _TESTS = [{
+        'url': 'http://www.youtube.com/show/airdisasters',
+        'playlist_mincount': 3,
+        'info_dict': {
+            'id': 'airdisasters',
+            'title': 'Air Disasters',
+        }
+    }]
 
     def _real_extract(self, url):
         mobj = re.match(self._VALID_URL, url)
-        show_name = mobj.group(1)
-        webpage = self._download_webpage(url, show_name, u'Downloading show webpage')
+        playlist_id = mobj.group('id')
+        webpage = self._download_webpage(
+            url, playlist_id, 'Downloading show webpage')
         # There's one playlist for each season of the show
         m_seasons = list(re.finditer(r'href="(/playlist\?list=.*?)"', webpage))
-        self.to_screen(u'%s: Found %s seasons' % (show_name, len(m_seasons)))
-        return [self.url_result('https://www.youtube.com' + season.group(1), 'YoutubePlaylist') for season in m_seasons]
+        self.to_screen('%s: Found %s seasons' % (playlist_id, len(m_seasons)))
+        entries = [
+            self.url_result(
+                'https://www.youtube.com' + season.group(1), 'YoutubePlaylist')
+            for season in m_seasons
+        ]
+        title = self._og_search_title(webpage, fatal=False)
+
+        return {
+            '_type': 'playlist',
+            'id': playlist_id,
+            'title': title,
+            'entries': entries,
+        }
 
 
 class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
@@ -1414,7 +1538,7 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
 
     @property
     def IE_NAME(self):
-        return u'youtube:%s' % self._FEED_NAME
+        return 'youtube:%s' % self._FEED_NAME
 
     def _real_initialize(self):
         self._login()
@@ -1424,9 +1548,10 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
         paging = 0
         for i in itertools.count(1):
             info = self._download_json(self._FEED_TEMPLATE % paging,
-                                          u'%s feed' % self._FEED_NAME,
-                                          u'Downloading page %s' % i)
+                                       '%s feed' % self._FEED_NAME,
+                                       'Downloading page %s' % i)
             feed_html = info.get('feed_html') or info.get('content_html')
+            load_more_widget_html = info.get('load_more_widget_html') or feed_html
             m_ids = re.finditer(r'"/watch\?v=(.*?)["&]', feed_html)
             ids = orderedSet(m.group(1) for m in m_ids)
             feed_entries.extend(
@@ -1434,51 +1559,56 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
                 for video_id in ids)
             mobj = re.search(
                 r'data-uix-load-more-href="/?[^"]+paging=(?P<paging>\d+)',
-                feed_html)
+                load_more_widget_html)
             if mobj is None:
                 break
             paging = mobj.group('paging')
         return self.playlist_result(feed_entries, playlist_title=self._PLAYLIST_TITLE)
 
+
 class YoutubeRecommendedIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'YouTube.com recommended videos, "ytrec" keyword (requires authentication)'
+    IE_DESC = 'YouTube.com recommended videos, ":ytrec" for short (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/feed/recommended|:ytrec(?:ommended)?'
     _FEED_NAME = 'recommended'
-    _PLAYLIST_TITLE = u'Youtube Recommended videos'
+    _PLAYLIST_TITLE = 'Youtube Recommended videos'
+
 
 class YoutubeWatchLaterIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'Youtube watch later list, "ytwatchlater" keyword (requires authentication)'
+    IE_DESC = 'Youtube watch later list, ":ytwatchlater" for short (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/feed/watch_later|:ytwatchlater'
     _FEED_NAME = 'watch_later'
-    _PLAYLIST_TITLE = u'Youtube Watch Later'
+    _PLAYLIST_TITLE = 'Youtube Watch Later'
     _PERSONAL_FEED = True
 
+
 class YoutubeHistoryIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'Youtube watch history, "ythistory" keyword (requires authentication)'
-    _VALID_URL = u'https?://www\.youtube\.com/feed/history|:ythistory'
+    IE_DESC = 'Youtube watch history, ":ythistory" for short (requires authentication)'
+    _VALID_URL = 'https?://www\.youtube\.com/feed/history|:ythistory'
     _FEED_NAME = 'history'
     _PERSONAL_FEED = True
-    _PLAYLIST_TITLE = u'Youtube Watch History'
+    _PLAYLIST_TITLE = 'Youtube Watch History'
+
 
 class YoutubeFavouritesIE(YoutubeBaseInfoExtractor):
-    IE_NAME = u'youtube:favorites'
-    IE_DESC = u'YouTube.com favourite videos, "ytfav" keyword (requires authentication)'
+    IE_NAME = 'youtube:favorites'
+    IE_DESC = 'YouTube.com favourite videos, ":ytfav" for short (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/my_favorites|:ytfav(?:ou?rites)?'
     _LOGIN_REQUIRED = True
 
     def _real_extract(self, url):
         webpage = self._download_webpage('https://www.youtube.com/my_favorites', 'Youtube Favourites videos')
-        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, u'favourites playlist id')
+        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, 'favourites playlist id')
         return self.url_result(playlist_id, 'YoutubePlaylist')
 
 
 class YoutubeSubscriptionsIE(YoutubePlaylistIE):
-    IE_NAME = u'youtube:subscriptions'
-    IE_DESC = u'YouTube.com subscriptions feed, "ytsubs" keyword (requires authentication)'
+    IE_NAME = 'youtube:subscriptions'
+    IE_DESC = 'YouTube.com subscriptions feed, "ytsubs" keyword (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/feed/subscriptions|:ytsubs(?:criptions)?'
+    _TESTS = []
 
     def _real_extract(self, url):
-        title = u'Youtube Subscriptions'
+        title = 'Youtube Subscriptions'
         page = self._download_webpage('https://www.youtube.com/feed/subscriptions', title)
 
         # The extraction process is the same as for playlists, but the regex
@@ -1530,9 +1660,9 @@ class YoutubeTruncatedURLIE(InfoExtractor):
 
     def _real_extract(self, url):
         raise ExtractorError(
-            u'Did you forget to quote the URL? Remember that & is a meta '
-            u'character in most shells, so you want to put the URL in quotes, '
-            u'like  youtube-dl '
-            u'"http://www.youtube.com/watch?feature=foo&v=BaW_jenozKc" '
-            u' or simply  youtube-dl BaW_jenozKc  .',
+            'Did you forget to quote the URL? Remember that & is a meta '
+            'character in most shells, so you want to put the URL in quotes, '
+            'like  youtube-dl '
+            '"http://www.youtube.com/watch?feature=foo&v=BaW_jenozKc" '
+            ' or simply  youtube-dl BaW_jenozKc  .',
             expected=True)