Merge 66ee6aa2da into c5098961b0

Now also succeeds with player b12cc44b

test/test_jsinterp.py

@@ -425,6 +425,34 @@ class TestJSInterpreter(unittest.TestCase):
             self._test(jsi, [''], args=['', '-'])
             self._test(jsi, [], args=['', ''])
 
+    def test_slice(self):
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice()}', [0, 1, 2, 3, 4, 5, 6, 7, 8])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(0)}', [0, 1, 2, 3, 4, 5, 6, 7, 8])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(5)}', [5, 6, 7, 8])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(99)}', [])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(-2)}', [7, 8])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(-99)}', [0, 1, 2, 3, 4, 5, 6, 7, 8])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(0, 0)}', [])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(1, 0)}', [])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(0, 1)}', [0])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(3, 6)}', [3, 4, 5])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(1, -1)}', [1, 2, 3, 4, 5, 6, 7])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(-1, 1)}', [])
+        self._test('function f(){return [0, 1, 2, 3, 4, 5, 6, 7, 8].slice(-3, -1)}', [6, 7])
+        self._test('function f(){return "012345678".slice()}', '012345678')
+        self._test('function f(){return "012345678".slice(0)}', '012345678')
+        self._test('function f(){return "012345678".slice(5)}', '5678')
+        self._test('function f(){return "012345678".slice(99)}', '')
+        self._test('function f(){return "012345678".slice(-2)}', '78')
+        self._test('function f(){return "012345678".slice(-99)}', '012345678')
+        self._test('function f(){return "012345678".slice(0, 0)}', '')
+        self._test('function f(){return "012345678".slice(1, 0)}', '')
+        self._test('function f(){return "012345678".slice(0, 1)}', '0')
+        self._test('function f(){return "012345678".slice(3, 6)}', '345')
+        self._test('function f(){return "012345678".slice(1, -1)}', '1234567')
+        self._test('function f(){return "012345678".slice(-1, 1)}', '')
+        self._test('function f(){return "012345678".slice(-3, -1)}', '67')
+
 
 if __name__ == '__main__':
     unittest.main()

test/test_youtube_signature.py

@@ -174,6 +174,14 @@ _NSIG_TESTS = [
         'https://www.youtube.com/s/player/5604538d/player_ias.vflset/en_US/base.js',
         '7X-he4jjvMx7BCX', 'sViSydX8IHtdWA',
     ),
+    (
+        'https://www.youtube.com/s/player/20dfca59/player_ias.vflset/en_US/base.js',
+        '-fLCxedkAk4LUTK2', 'O8kfRq1y1eyHGw',
+    ),
+    (
+        'https://www.youtube.com/s/player/b12cc44b/player_ias.vflset/en_US/base.js',
+        'keLa5R2U00sR9SQK', 'N1OGyujjEwMnLw',
+    ),
 ]
 
 

youtube_dl/extractor/common.py

@@ -1370,6 +1370,10 @@ class InfoExtractor(object):
         if isinstance(json_ld, dict):
             json_ld = [json_ld]
 
+        def valued_dict(items):
+            """Return dict from dict or iterable of pairs omitting None values"""
+            return dict((k, v) for k, v in (items.items() if isinstance(items, dict) else items) if v is not None)
+
         INTERACTION_TYPE_MAP = {
             'CommentAction': 'comment',
             'AgreeAction': 'like',
@@ -1461,19 +1465,25 @@ class InfoExtractor(object):
                     part_of_series = e.get('partOfSeries') or e.get('partOfTVSeries')
                     if isinstance(part_of_series, dict) and part_of_series.get('@type') in ('TVSeries', 'Series', 'CreativeWorkSeries'):
                         info['series'] = unescapeHTML(part_of_series.get('name'))
-                elif item_type == 'Movie':
+                elif item_type in ('TVSeries', 'Series', 'CreativeWorkSeries'):
+                    series_name = unescapeHTML(e.get('name'))
                     info.update({
+                        'series': series_name,
+                    })
+                elif item_type == 'Movie':
+                    # here and in the next, don't erase existing value with None
+                    info.update(valued_dict({
                         'title': unescapeHTML(e.get('name')),
                         'description': unescapeHTML(e.get('description')),
                         'duration': parse_duration(e.get('duration')),
                         'timestamp': unified_timestamp(e.get('dateCreated')),
-                    })
+                    }))
                 elif item_type in ('Article', 'NewsArticle'):
-                    info.update({
+                    info.update(valued_dict({
                         'timestamp': parse_iso8601(e.get('datePublished')),
                         'title': unescapeHTML(e.get('headline')),
                         'description': unescapeHTML(e.get('articleBody')),
-                    })
+                    }))
                 elif item_type == 'VideoObject':
                     extract_video_object(e)
                     if expected_type is None:
@@ -1487,7 +1497,7 @@ class InfoExtractor(object):
                     continue
                 else:
                     break
-        return dict((k, v) for k, v in info.items() if v is not None)
+        return valued_dict(info)
 
     def _search_nextjs_data(self, webpage, video_id, **kw):
         # ..., *, transform_source=None, fatal=True, default=NO_DEFAULT

youtube_dl/extractor/extractors.py

@@ -1325,6 +1325,10 @@ from .trovo import (
     TrovoIE,
     TrovoVodIE,
 )
+from .trt import (
+    TRTIE,
+    TRTLiveIE,
+)
 from .trunews import TruNewsIE
 from .trutv import TruTVIE
 from .tube8 import Tube8IE

youtube_dl/extractor/trt.py

@@ -0,0 +1,325 @@
+# coding: utf-8
+from __future__ import unicode_literals
+
+import json
+import re
+import time
+
+from .common import InfoExtractor
+
+from ..compat import (
+    compat_urlparse,
+)
+from ..utils import (
+    determine_ext,
+    dict_get,
+    merge_dicts,
+    parse_iso8601,
+    strip_or_none,
+    try_get,
+    url_or_none,
+    urljoin,
+)
+
+
+class TRTIE(InfoExtractor):
+    IE_DESC = 'TRT (Turkish State TV) programs and series'
+    _VALID_URL = r'''(?x)
+                     (?P<list>https?://(?:www\.)trtizle\.com/
+                         (?:diziler|programlar|belgesel|filmler|cocuk|trtarsiv|engelsiz)/
+                             (?P<show>[\w-]+))(?:/(?P<id>[\w-]+))?'''
+    _TESTS = [{
+        'url': 'https://www.trtizle.com/belgesel/dunya-tarihinin-donum-noktalari/dunya-tarihinin-donum-noktalari-1-bolum-125583',
+        'md5': 'c46dc0b9b53ad372c4ac6b3982805f05',
+        'info_dict': {
+            'id': 'dunya-tarihinin-donum-noktalari-1-bolum-125583',
+            'ext': 'mp4',
+            'title': 'Dünya Tarihinin Dönüm Noktaları 1.Bölüm',
+            'description': 'Bedelini insanların ödeyeceği bir imparatorluk çekişmesinde Persler, Yunanlara karşı...',
+            'timestamp': 1617148800,
+            'upload_date': '20210331',
+            'thumbnail': r're:https?://.+\.jpe?g',
+            'duration': float,
+            'series': 'Dünya Tarihinin Dönüm Noktaları',
+        },
+        'params': {
+            # adaptive download
+            'skip_download': True,
+        }
+    }, {
+        'url': 'https://www.trtizle.com/belgesel/dunya-tarihinin-donum-noktalari',
+        'info_dict': {
+            'id': 'dunya-tarihinin-donum-noktalari',
+            'title': 'Dünya Tarihinin Dönüm Noktaları',
+        },
+        'playlist_mincount': 22,
+    }, {
+        'url': 'https://www.trtizle.com/diziler/yol-ayrimi/yol-ayrimi-1-bolum-5774583',
+        'md5': '67ada6b2020b5dd0d3e24646b2725676',
+        'info_dict': {
+            'id': 'yol-ayrimi-1-bolum-5774583',
+            'ext': 'mp4',
+            'title': 'Yol Ayrımı 1.Bölüm',
+            'description': 'Seyrisefain balosunda, herkes bir haberin akıbetini beklemektedir…',
+            'timestamp': 1623888000,
+            'upload_date': '20210617',
+            'thumbnail': r're:https?://.+\.jpe?g',
+            'duration': float,
+            'series': 'Yol Ayrımı',
+        },
+        'params': {
+            # adaptive download
+            'skip_download': True,
+        },
+    }, {
+        'url': 'https://www.trtizle.com/diziler/yol-ayrimi/',
+        'info_dict': {
+            'id': 'yol-ayrimi',
+            'title': 'Yol Ayrımı',
+        },
+        'playlist_mincount': 5,
+    }, {
+        'url': 'https://www.trtizle.com/programlar/sade-saz/sade-saz-1-bolum-7646201',
+        'md5': '8f416e64379ea4d1d3ea0a65dc922f5c',
+        'info_dict': {
+            'id': 'sade-saz-1-bolum-7646201',
+            'ext': 'mp4',
+            'title': 'Sade Saz 1.Bölüm',
+            'description': 'Sade Saz’ın ilk bölümünün konuğu, tanbur icracısı K. Alper Uzkur.',
+            'timestamp': 1641772800,
+            'upload_date': '20220110',
+            'thumbnail': r're:https?://.+\.jpe?g',
+            'duration': float,
+            'series': 'Sade Saz',
+        },
+        'params': {
+            # adaptive download
+            'skip_download': True,
+        },
+    }, {
+        'url': 'https://www.trtizle.com/programlar/sade-saz',
+        'info_dict': {
+            'id': 'sade-saz',
+            'title': 'Sade Saz',
+        },
+        'playlist_mincount': 6,
+    }, {
+        'url': 'https://www.trtizle.com/filmler/looking-for-eric/looking-for-eric-8414201',
+        'md5': '833d61e4a10606d71b3903295cfa3c63',
+        'info_dict': {
+            'id': 'looking-for-eric-8414201',
+            'ext': 'mp4',
+            'title': 'Looking for Eric',
+            'description': 'Postacı Eric\'in hayatı krize sürüklenirken gerçek ve hayal birbirine karışır...',
+            'upload_date': '20220401',
+            'timestamp': 1648771200,
+            'thumbnail': r're:https?://.+\.jpe?g',
+            'duration': float,
+        },
+        'params': {
+            # adaptive download
+            'skip_download': True,
+        },
+    }, {
+        'url': 'https://www.trtizle.com/cocuk/kaptan-pengu-ve-arkadaslari/kaptan-pengu-ve-arkadaslari-okul-aciliyor-6034815',
+        'md5': '551c479d1a6bc7c538356907d4ea5d19',
+        'info_dict': {
+            'id': 'kaptan-pengu-ve-arkadaslari-okul-aciliyor-6034815',
+            'ext': 'mp4',
+            'title': 'Kaptan Pengu ve Arkadaşları 1.Bölüm',
+            'description': 'Hayvanlar Konseyi\'nden Kaptan Pengu\'ya bir mektup vardır...',
+            'timestamp': 1626134400,
+            'upload_date': '20210713',
+            'thumbnail': r're:https?://.+\.jpe?g',
+            'duration': float,
+            'series': 'Kaptan Pengu ve Arkadaşları',
+        },
+        'params': {
+            # adaptive download
+            'skip_download': True,
+        },
+    }, {
+        'url': 'https://www.trtizle.com/cocuk/kaptan-pengu-ve-arkadaslari',
+        'info_dict': {
+            'id': 'kaptan-pengu-ve-arkadaslari',
+            'title': 'Kaptan Pengu ve Arkadaşları',
+        },
+        'playlist_mincount': 41,
+    },
+    ]
+
+    def _extract_formats(self, fmt_url, video_id):
+        formats = []
+        ext = determine_ext(fmt_url)
+        if ext == 'm3u8':
+            formats.extend(self._extract_m3u8_formats(
+                fmt_url, video_id, 'mp4', entry_protocol='m3u8_native',
+                m3u8_id='hls', fatal=False))
+        elif ext == 'mpd':
+            formats.extend(self._extract_mpd_formats(
+                fmt_url, video_id, mpd_id='dash', fatal=False))
+        else:
+            formats.append({
+                'url': fmt_url,
+            })
+        return formats
+
+    def _extract_list(self, playlist_id, url):
+        webpage = self._download_webpage(url, playlist_id)
+        LIST_RE = (
+            r'''<a\s[^>]*?\b%s\s*=\s*['"](%s(?:(?<=/)|/)[\w-]+)'''
+            % ('data-path' if 'data-path' in webpage else 'href',
+               re.escape(compat_urlparse.urlparse(url).path), ))
+
+        def entries():
+            for item_url in re.finditer(LIST_RE, webpage):
+                item_url = urljoin(url, item_url.group(1))
+                yield self._extract_video(self._match_id(item_url), item_url)
+
+        series = self._search_json_ld(webpage, playlist_id, default={}, expected_type='TVSeries')
+        return self.playlist_result(entries(), playlist_id, series.get('series'))
+
+    def _extract_video(self, video_id, url):
+        webpage = self._download_webpage(url, video_id)
+        result = self._search_json_ld(webpage, video_id, default={})
+        result['id'] = video_id
+        if 'title' not in result:
+            result['title'] = (
+                self._html_search_meta(('title', 'og:title', 'twitter:title'), webpage)
+                or self._html_search_regex(r'<title\b[^>]*>([^<]+)</title\b', webpage, 'title'))
+        fmt_url = result.get('url')
+        formats = []
+        if fmt_url:
+            del result['url']
+            formats = self._extract_formats(fmt_url, video_id)
+        self._sort_formats(formats)
+        result['formats'] = formats
+
+        return merge_dicts(
+            result, {
+                'description': self._html_search_meta(('description', 'og:description'), webpage, 'description'),
+                'thumbnail': url_or_none(self._og_search_thumbnail(webpage)),
+            })
+
+    def _real_extract(self, url):
+        show_id, video_id, playlist_url = re.match(self._VALID_URL, url).group('show', 'id', 'list')
+        # TODO: adapt --yes/no-playlist to make this work properly
+        # if not video_id or self._downloader.params.get('noplaylist') is False:
+        if not video_id:
+            return self._extract_list(show_id, playlist_url)
+
+        return self._extract_video(video_id, url)
+
+
+class TRTLiveIE(TRTIE):
+    IE_DESC = 'TRT (Turkish State TV and radio) live channels'
+    _VALID_URL = r'https?://(?:www\.)?trtizle\.com/canli/(?:tv/trt-|radyo/(?:radyo-)?)(?P<id>[\w-]+)'
+    _TESTS = [{
+        'url': 'https://www.trtizle.com/canli/tv/trt-world',
+        'info_dict': {
+            'id': 'trtworld',
+            'ext': 'mp4',
+            'title': r're:TRT WORLD .+',
+            'description': 'TRT World',
+            'is_live': True,
+        },
+        'params': {
+            # adaptive download
+            'skip_download': True,
+        }
+    },
+    ]
+
+    def _real_extract(self, url):
+        chan_id = self._match_id(url)
+        webpage = self._download_webpage(url, chan_id)
+        chan_id = self._search_regex(
+            r'\blivePlayer\s*\.\s*openPlayer\s*\([^)]*?\btrt\.com\.tr/trtportal/(?:[^/]+/)+thumbnails/([\w-]+)\.(?:jp|png)',
+            webpage, 'slug', fatal=False) or chan_id
+        chan_url = self._search_regex(
+            r'''\blivePlayerConfig\s*\.\s*baseEpgUrl\s*=\s*(?P<q>'|")(?P<url>https?://(?:(?!(?P=q)).)+)(?P=q)''',
+            webpage, 'player config', group='url')
+        chan_url = '%s%s.json' % (chan_url, chan_id)
+
+        def maybe_xml2json(src):
+            """Turn unexpected XML returned from an API URL into JSON"""
+            m = re.match(r'''^\s*<\?xml\b(?:[^/>]*?\bencoding\s*=\s*['"](?P<enc>[\w-]+))?[^/>]*\?>\s*(?P<xml><.+>)$''', src)
+            if m:
+
+                # Thanks https://stackoverflow.com/a/63556250 for inspiration
+                ATTR_RE = (
+                    r"""(?s)(?P<avr>\S ?)(?:\s*=\s*(?P<q>['"])(?P<avl>.*?)(?<!\\)(?P=q))?"""
+                )
+
+                def elt_value(attr_str, val_dict):
+                    v = {}
+                    attrs = dict((j.group("avr"), j.groupdict(True).get("avl"))
+                                 for j in re.finditer(ATTR_RE, attr_str.strip()))
+                    if attrs:
+                        v['@attributes'] = attrs
+                    v['@values'] = val_dict
+                    return v
+
+                def xml2dict(xml_str):
+                    elts = re.findall(
+                        r"(?s)<(?P<var>\S )(?P<attr>[^/>]*)(?:(?:>(?P<val>.*?)</(?P=var)>)|(?:/>))",
+                        xml_str,
+                    )
+
+                    if elts:
+                        elts = [{i[0]: elt_value(i[1], xml2dict(i[2]))} for i in elts]
+                        if len(elts) == 1:
+                            return elts[0]
+                        return elts
+                    return xml_str
+
+                try:
+                    return json.dumps(xml2dict(m.group('xml').encode(m.group('enc') or 'utf-8')))
+                except Exception:
+                    pass
+            return src
+
+        chan_info = self._download_json(
+            chan_url, chan_id, fatal=False,
+            note='Downloading player EPG JSON',
+            query={'_': int(time.time() * 1000)},
+            expected_status=403,
+            # errors are returned as XML
+            transform_source=maybe_xml2json)
+        if not isinstance(chan_info, dict) or 'Error' in chan_info:
+            chan_info = self._download_json(
+                'https://trtizle-api.cdn.wp.trt.com.tr/trttv/v3/livestream',
+                chan_id, fatal=False,
+                note='Downloading livestream API JSON',
+                query={'path': compat_urlparse.urlparse(url).path}) or {}
+
+        title = chan_info['channel']['title']
+
+        current = try_get(chan_info, lambda x: x['current'], dict) or {}
+        if current.get('geo_block'):
+            self._downloader.report_warning(
+                '[%s] %s' % (self.IE_NAME, 'Stream is geo-blocked'))
+
+        chan_info = chan_info['channel']
+        fmt_url = dict_get(chan_info, ('url', 'noneDvrUrl'))
+        formats = []
+        if fmt_url:
+            formats = self._extract_formats(fmt_url, chan_id)
+        self._sort_formats(formats)
+
+        start_end = [parse_iso8601(current.get(x)) for x in ('starttime', 'endtime')]
+        if None in start_end:
+            start_end = None
+
+        return {
+            'id': chan_id,
+            'title': self._live_title(current.get('title') or title),
+            'is_live': True,
+            'formats': formats,
+            'description': strip_or_none(chan_info.get('description')),
+            'thumbnail': next((url_or_none(chan_info.get(x))
+                              for x in ('thumbnail', 'thumbnailYoutubeUrl', 'square_logo', 'livestreamLogoUrl')),
+                              None),
+            'timestamp': start_end and start_end[0],
+            'duration': start_end and (start_end[1] - time.time()),
+        }

youtube_dl/extractor/youtube.py

@@ -1659,17 +1659,46 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
     def _extract_n_function_name(self, jscode):
         func_name, idx = self._search_regex(
             # new: (b=String.fromCharCode(110),c=a.get(b))&&c=nfunc[idx](c)
-            # or:  (b="nn"[+a.D],c=a.get(b))&&(c=nfunc[idx](c)s
-            # old: .get("n"))&&(b=nfunc[idx](b)
-            # older: .get("n"))&&(b=nfunc(b)
+            # or:  (b="nn"[+a.D],c=a.get(b))&&(c=nfunc[idx](c)
+            # or:  (PL(a),b=a.j.n||null)&&(b=nfunc[idx](b)
+            # or:  (b="nn"[+a.D],vL(a),c=a.j[b]||null)&&(c=narray[idx](c),a.set(b,c),narray.length||nfunc("")
+            # old: (b=a.get("n"))&&(b=nfunc[idx](b)(?P<c>[a-z])\s*=\s*[a-z]\s*
+            # older: (b=a.get("n"))&&(b=nfunc(b)
             r'''(?x)
-                (?:\(\s*(?P<b>[a-z])\s*=\s*(?:
+                \((?:[\w$()\s]+,)*?\s*      # (
+                (?P<b>[a-z])\s*=\s*         # b=
+                (?:
+                    (?:                     # expect ,c=a.get(b) (etc)
                         String\s*\.\s*fromCharCode\s*\(\s*110\s*\)|
                         "n+"\[\s*\+?s*[\w$.]+\s*]
-                )\s*,(?P<c>[a-z])\s*=\s*[a-z]\s*)?
-                \.\s*get\s*\(\s*(?(b)(?P=b)|"n{1,2}")(?:\s*\)){2}\s*&&\s*\(\s*(?(c)(?P=c)|b)\s*=\s*
+                    )\s*(?:,[\w$()\s]+(?=,))*|
+                       (?P<old>[\w$]+)      # a (old[er])
+                   )\s*
+                   (?(old)
+                                            # b.get("n")
+                       (?:\.\s*[\w$]+\s*|\[\s*[\w$]+\s*]\s*)*?
+                       (?:\.\s*n|\[\s*"n"\s*]|\.\s*get\s*\(\s*"n"\s*\))
+                       |                    # ,c=a.get(b)
+                       ,\s*(?P<c>[a-z])\s*=\s*[a-z]\s*
+                       (?:\.\s*[\w$]+\s*|\[\s*[\w$]+\s*]\s*)*?
+                       (?:\[\s*(?P=b)\s*]|\.\s*get\s*\(\s*(?P=b)\s*\))
+                   )
+                                            # interstitial junk
+                   \s*(?:\|\|\s*null\s*)?(?:\)\s*)?&&\s*(?:\(\s*)?
+               (?(c)(?P=c)|(?P=b))\s*=\s*   # [c|b]=
+                                            # nfunc|nfunc[idx]
                    (?P<nfunc>[a-zA-Z_$][\w$]*)(?:\s*\[(?P<idx>\d+)\])?\s*\(\s*[\w$]+\s*\)
-            ''', jscode, 'Initial JS player n function name', group=('nfunc', 'idx'))
+            ''', jscode, 'Initial JS player n function name', group=('nfunc', 'idx'),
+            default=(None, None))
+        # thx bashonly: yt-dlp/yt-dlp/pull/10611
+        if not func_name:
+            self.report_warning('Falling back to generic n function search')
+            return self._search_regex(
+                r'''(?xs)
+                    (?:(?<=[^\w$])|^)       # instead of \b, which ignores $
+                    (?P<name>(?!\d)[a-zA-Z\d_$]+)\s*=\s*function\((?!\d)[a-zA-Z\d_$]+\)
+                    \s*\{(?:(?!};).)+?["']enhanced_except_
+                ''', jscode, 'Initial JS player n function name', group='name')
         if not idx:
             return func_name
 

youtube_dl/jsinterp.py

@@ -925,9 +925,16 @@ class JSInterpreter(object):
                     obj.reverse()
                     return obj
                 elif member == 'slice':
-                    assertion(isinstance(obj, list), 'must be applied on a list')
-                    assertion(len(argvals) == 1, 'takes exactly one argument')
-                    return obj[argvals[0]:]
+                    assertion(isinstance(obj, (list, compat_str)), 'must be applied on a list or string')
+                    # From [1]:
+                    # .slice() - like [:]
+                    # .slice(n) - like [n:] (not [slice(n)]
+                    # .slice(m, n) - like [m:n] or [slice(m, n)]
+                    # [1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice
+                    assertion(len(argvals) <= 2, 'takes between 0 and 2 arguments')
+                    if len(argvals) < 2:
+                        argvals += (None,)
+                    return obj[slice(*argvals)]
                 elif member == 'splice':
                     assertion(isinstance(obj, list), 'must be applied on a list')
                     assertion(argvals, 'takes one or more arguments')