[utils] Split out traversal.py dummy and traversal tests

3 files changed, 519 insertions, 483 deletions

diff --git a/test/test_traversal.py b/test/test_traversal.py
new file mode 100644
index 000000000..00a428edb
--- /dev/null
+++ b/test/test_traversal.py
@@ -0,0 +1,509 @@
+#!/usr/bin/env python
+# coding: utf-8
+from __future__ import unicode_literals
+
+# Allow direct execution
+import os
+import sys
+import unittest
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+
+import re
+
+from youtube_dl.traversal import (
+    dict_get,
+    get_first,
+    T,
+    traverse_obj,
+)
+from youtube_dl.compat import (
+    compat_etree_fromstring,
+    compat_http_cookies,
+    compat_str,
+)
+from youtube_dl.utils import (
+    int_or_none,
+    str_or_none,
+)
+
+_TEST_DATA = {
+    100: 100,
+    1.2: 1.2,
+    'str': 'str',
+    'None': None,
+    '...': Ellipsis,
+    'urls': [
+        {'index': 0, 'url': 'https://www.example.com/0'},
+        {'index': 1, 'url': 'https://www.example.com/1'},
+    ],
+    'data': (
+        {'index': 2},
+        {'index': 3},
+    ),
+    'dict': {},
+}
+
+
+if sys.version_info < (3, 0):
+    class _TestCase(unittest.TestCase):
+
+        def assertCountEqual(self, *args, **kwargs):
+            return self.assertItemsEqual(*args, **kwargs)
+else:
+    _TestCase = unittest.TestCase
+
+
+class TestTraversal(_TestCase):
+    def assertMaybeCountEqual(self, *args, **kwargs):
+        if sys.version_info < (3, 7):
+            # random dict order
+            return self.assertCountEqual(*args, **kwargs)
+        else:
+            return self.assertEqual(*args, **kwargs)
+
+    def test_traverse_obj(self):
+        # instant compat
+        str = compat_str
+
+        # define a pukka Iterable
+        def iter_range(stop):
+            for from_ in range(stop):
+                yield from_
+
+        # Test base functionality
+        self.assertEqual(traverse_obj(_TEST_DATA, ('str',)), 'str',
+                         msg='allow tuple path')
+        self.assertEqual(traverse_obj(_TEST_DATA, ['str']), 'str',
+                         msg='allow list path')
+        self.assertEqual(traverse_obj(_TEST_DATA, (value for value in ("str",))), 'str',
+                         msg='allow iterable path')
+        self.assertEqual(traverse_obj(_TEST_DATA, 'str'), 'str',
+                         msg='single items should be treated as a path')
+        self.assertEqual(traverse_obj(_TEST_DATA, None), _TEST_DATA)
+        self.assertEqual(traverse_obj(_TEST_DATA, 100), 100)
+        self.assertEqual(traverse_obj(_TEST_DATA, 1.2), 1.2)
+
+        # Test Ellipsis behavior
+        self.assertCountEqual(traverse_obj(_TEST_DATA, Ellipsis),
+                              (item for item in _TEST_DATA.values() if item not in (None, {})),
+                              msg='`...` should give all non-discarded values')
+        self.assertCountEqual(traverse_obj(_TEST_DATA, ('urls', 0, Ellipsis)), _TEST_DATA['urls'][0].values(),
+                              msg='`...` selection for dicts should select all values')
+        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, Ellipsis, 'url')),
+                         ['https://www.example.com/0', 'https://www.example.com/1'],
+                         msg='nested `...` queries should work')
+        self.assertCountEqual(traverse_obj(_TEST_DATA, (Ellipsis, Ellipsis, 'index')), iter_range(4),
+                              msg='`...` query result should be flattened')
+        self.assertEqual(traverse_obj(iter(range(4)), Ellipsis), list(range(4)),
+                         msg='`...` should accept iterables')
+
+        # Test function as key
+        self.assertEqual(traverse_obj(_TEST_DATA, lambda x, y: x == 'urls' and isinstance(y, list)),
+                         [_TEST_DATA['urls']],
+                         msg='function as query key should perform a filter based on (key, value)')
+        self.assertCountEqual(traverse_obj(_TEST_DATA, lambda _, x: isinstance(x[0], str)), set(('str',)),
+                              msg='exceptions in the query function should be caught')
+        self.assertEqual(traverse_obj(iter(range(4)), lambda _, x: x % 2 == 0), [0, 2],
+                         msg='function key should accept iterables')
+        if __debug__:
+            with self.assertRaises(Exception, msg='Wrong function signature should raise in debug'):
+                traverse_obj(_TEST_DATA, lambda a: Ellipsis)
+            with self.assertRaises(Exception, msg='Wrong function signature should raise in debug'):
+                traverse_obj(_TEST_DATA, lambda a, b, c: Ellipsis)
+
+        # Test set as key (transformation/type, like `expected_type`)
+        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str.upper), )), ['STR'],
+                         msg='Function in set should be a transformation')
+        self.assertEqual(traverse_obj(_TEST_DATA, ('fail', T(lambda _: 'const'))), 'const',
+                         msg='Function in set should always be called')
+        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str))), ['str'],
+                         msg='Type in set should be a type filter')
+        self.assertMaybeCountEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str, int))), [100, 'str'],
+                                   msg='Multiple types in set should be a type filter')
+        self.assertEqual(traverse_obj(_TEST_DATA, T(dict)), _TEST_DATA,
+                         msg='A single set should be wrapped into a path')
+        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str.upper))), ['STR'],
+                         msg='Transformation function should not raise')
+        self.assertMaybeCountEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str_or_none))),
+                                   [item for item in map(str_or_none, _TEST_DATA.values()) if item is not None],
+                                   msg='Function in set should be a transformation')
+        if __debug__:
+            with self.assertRaises(Exception, msg='Sets with length != 1 should raise in debug'):
+                traverse_obj(_TEST_DATA, set())
+            with self.assertRaises(Exception, msg='Sets with length != 1 should raise in debug'):
+                traverse_obj(_TEST_DATA, set((str.upper, str)))
+
+        # Test `slice` as a key
+        _SLICE_DATA = [0, 1, 2, 3, 4]
+        self.assertEqual(traverse_obj(_TEST_DATA, ('dict', slice(1))), None,
+                         msg='slice on a dictionary should not throw')
+        self.assertEqual(traverse_obj(_SLICE_DATA, slice(1)), _SLICE_DATA[:1],
+                         msg='slice key should apply slice to sequence')
+        self.assertEqual(traverse_obj(_SLICE_DATA, slice(1, 2)), _SLICE_DATA[1:2],
+                         msg='slice key should apply slice to sequence')
+        self.assertEqual(traverse_obj(_SLICE_DATA, slice(1, 4, 2)), _SLICE_DATA[1:4:2],
+                         msg='slice key should apply slice to sequence')
+
+        # Test alternative paths
+        self.assertEqual(traverse_obj(_TEST_DATA, 'fail', 'str'), 'str',
+                         msg='multiple `paths` should be treated as alternative paths')
+        self.assertEqual(traverse_obj(_TEST_DATA, 'str', 100), 'str',
+                         msg='alternatives should exit early')
+        self.assertEqual(traverse_obj(_TEST_DATA, 'fail', 'fail'), None,
+                         msg='alternatives should return `default` if exhausted')
+        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, 'fail'), 100), 100,
+                         msg='alternatives should track their own branching return')
+        self.assertEqual(traverse_obj(_TEST_DATA, ('dict', Ellipsis), ('data', Ellipsis)), list(_TEST_DATA['data']),
+                         msg='alternatives on empty objects should search further')
+
+        # Test branch and path nesting
+        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', (3, 0), 'url')), ['https://www.example.com/0'],
+                         msg='tuple as key should be treated as branches')
+        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', [3, 0], 'url')), ['https://www.example.com/0'],
+                         msg='list as key should be treated as branches')
+        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', ((1, 'fail'), (0, 'url')))), ['https://www.example.com/0'],
+                         msg='double nesting in path should be treated as paths')
+        self.assertEqual(traverse_obj(['0', [1, 2]], [(0, 1), 0]), [1],
+                         msg='do not fail early on branching')
+        self.assertCountEqual(traverse_obj(_TEST_DATA, ('urls', ((1, ('fail', 'url')), (0, 'url')))),
+                              ['https://www.example.com/0', 'https://www.example.com/1'],
+                              msg='triple nesting in path should be treated as branches')
+        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', ('fail', (Ellipsis, 'url')))),
+                         ['https://www.example.com/0', 'https://www.example.com/1'],
+                         msg='ellipsis as branch path start gets flattened')
+
+        # Test dictionary as key
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 100, 1: 1.2}), {0: 100, 1: 1.2},
+                         msg='dict key should result in a dict with the same keys')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', 0, 'url')}),
+                         {0: 'https://www.example.com/0'},
+                         msg='dict key should allow paths')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', (3, 0), 'url')}),
+                         {0: ['https://www.example.com/0']},
+                         msg='tuple in dict path should be treated as branches')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', ((1, 'fail'), (0, 'url')))}),
+                         {0: ['https://www.example.com/0']},
+                         msg='double nesting in dict path should be treated as paths')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', ((1, ('fail', 'url')), (0, 'url')))}),
+                         {0: ['https://www.example.com/1', 'https://www.example.com/0']},
+                         msg='triple nesting in dict path should be treated as branches')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'fail'}), {},
+                         msg='remove `None` values when top level dict key fails')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'fail'}, default=Ellipsis), {0: Ellipsis},
+                         msg='use `default` if key fails and `default`')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'dict'}), {},
+                         msg='remove empty values when dict key')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'dict'}, default=Ellipsis), {0: Ellipsis},
+                         msg='use `default` when dict key and a default')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: {0: 'fail'}}), {},
+                         msg='remove empty values when nested dict key fails')
+        self.assertEqual(traverse_obj(None, {0: 'fail'}), {},
+                         msg='default to dict if pruned')
+        self.assertEqual(traverse_obj(None, {0: 'fail'}, default=Ellipsis), {0: Ellipsis},
+                         msg='default to dict if pruned and default is given')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: {0: 'fail'}}, default=Ellipsis), {0: {0: Ellipsis}},
+                         msg='use nested `default` when nested dict key fails and `default`')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('dict', Ellipsis)}), {},
+                         msg='remove key if branch in dict key not successful')
+
+        # Testing default parameter behavior
+        _DEFAULT_DATA = {'None': None, 'int': 0, 'list': []}
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'fail'), None,
+                         msg='default value should be `None`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'fail', 'fail', default=Ellipsis), Ellipsis,
+                         msg='chained fails should result in default')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'None', 'int'), 0,
+                         msg='should not short cirquit on `None`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'fail', default=1), 1,
+                         msg='invalid dict key should result in `default`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'None', default=1), 1,
+                         msg='`None` is a deliberate sentinel and should become `default`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, ('list', 10)), None,
+                         msg='`IndexError` should result in `default`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, (Ellipsis, 'fail'), default=1), 1,
+                         msg='if branched but not successful return `default` if defined, not `[]`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, (Ellipsis, 'fail'), default=None), None,
+                         msg='if branched but not successful return `default` even if `default` is `None`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, (Ellipsis, 'fail')), [],
+                         msg='if branched but not successful return `[]`, not `default`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, ('list', Ellipsis)), [],
+                         msg='if branched but object is empty return `[]`, not `default`')
+        self.assertEqual(traverse_obj(None, Ellipsis), [],
+                         msg='if branched but object is `None` return `[]`, not `default`')
+        self.assertEqual(traverse_obj({0: None}, (0, Ellipsis)), [],
+                         msg='if branched but state is `None` return `[]`, not `default`')
+
+        branching_paths = [
+            ('fail', Ellipsis),
+            (Ellipsis, 'fail'),
+            100 * ('fail',) + (Ellipsis,),
+            (Ellipsis,) + 100 * ('fail',),
+        ]
+        for branching_path in branching_paths:
+            self.assertEqual(traverse_obj({}, branching_path), [],
+                             msg='if branched but state is `None`, return `[]` (not `default`)')
+            self.assertEqual(traverse_obj({}, 'fail', branching_path), [],
+                             msg='if branching in last alternative and previous did not match, return `[]` (not `default`)')
+            self.assertEqual(traverse_obj({0: 'x'}, 0, branching_path), 'x',
+                             msg='if branching in last alternative and previous did match, return single value')
+            self.assertEqual(traverse_obj({0: 'x'}, branching_path, 0), 'x',
+                             msg='if branching in first alternative and non-branching path does match, return single value')
+            self.assertEqual(traverse_obj({}, branching_path, 'fail'), None,
+                             msg='if branching in first alternative and non-branching path does not match, return `default`')
+
+        # Testing expected_type behavior
+        _EXPECTED_TYPE_DATA = {'str': 'str', 'int': 0}
+        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=str),
+                         'str', msg='accept matching `expected_type` type')
+        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=int),
+                         None, msg='reject non-matching `expected_type` type')
+        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'int', expected_type=lambda x: str(x)),
+                         '0', msg='transform type using type function')
+        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=lambda _: 1 / 0),
+                         None, msg='wrap expected_type function in try_call')
+        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, Ellipsis, expected_type=str),
+                         ['str'], msg='eliminate items that expected_type fails on')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 100, 1: 1.2}, expected_type=int),
+                         {0: 100}, msg='type as expected_type should filter dict values')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 100, 1: 1.2, 2: 'None'}, expected_type=str_or_none),
+                         {0: '100', 1: '1.2'}, msg='function as expected_type should transform dict values')
+        self.assertEqual(traverse_obj(_TEST_DATA, ({0: 1.2}, 0, set((int_or_none,))), expected_type=int),
+                         1, msg='expected_type should not filter non-final dict values')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: {0: 100, 1: 'str'}}, expected_type=int),
+                         {0: {0: 100}}, msg='expected_type should transform deep dict values')
+        self.assertEqual(traverse_obj(_TEST_DATA, [({0: '...'}, {0: '...'})], expected_type=type(Ellipsis)),
+                         [{0: Ellipsis}, {0: Ellipsis}], msg='expected_type should transform branched dict values')
+        self.assertEqual(traverse_obj({1: {3: 4}}, [(1, 2), 3], expected_type=int),
+                         [4], msg='expected_type regression for type matching in tuple branching')
+        self.assertEqual(traverse_obj(_TEST_DATA, ['data', Ellipsis], expected_type=int),
+                         [], msg='expected_type regression for type matching in dict result')
+
+        # Test get_all behavior
+        _GET_ALL_DATA = {'key': [0, 1, 2]}
+        self.assertEqual(traverse_obj(_GET_ALL_DATA, ('key', Ellipsis), get_all=False), 0,
+                         msg='if not `get_all`, return only first matching value')
+        self.assertEqual(traverse_obj(_GET_ALL_DATA, Ellipsis, get_all=False), [0, 1, 2],
+                         msg='do not overflatten if not `get_all`')
+
+        # Test casesense behavior
+        _CASESENSE_DATA = {
+            'KeY': 'value0',
+            0: {
+                'KeY': 'value1',
+                0: {'KeY': 'value2'},
+            },
+            # FULLWIDTH LATIN CAPITAL LETTER K
+            '\uff2bey': 'value3',
+        }
+        self.assertEqual(traverse_obj(_CASESENSE_DATA, 'key'), None,
+                         msg='dict keys should be case sensitive unless `casesense`')
+        self.assertEqual(traverse_obj(_CASESENSE_DATA, 'keY',
+                                      casesense=False), 'value0',
+                         msg='allow non matching key case if `casesense`')
+        self.assertEqual(traverse_obj(_CASESENSE_DATA, '\uff4bey',  # FULLWIDTH LATIN SMALL LETTER K
+                                      casesense=False), 'value3',
+                         msg='allow non matching Unicode key case if `casesense`')
+        self.assertEqual(traverse_obj(_CASESENSE_DATA, (0, ('keY',)),
+                                      casesense=False), ['value1'],
+                         msg='allow non matching key case in branch if `casesense`')
+        self.assertEqual(traverse_obj(_CASESENSE_DATA, (0, ((0, 'keY'),)),
+                                      casesense=False), ['value2'],
+                         msg='allow non matching key case in branch path if `casesense`')
+
+        # Test traverse_string behavior
+        _TRAVERSE_STRING_DATA = {'str': 'str', 1.2: 1.2}
+        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', 0)), None,
+                         msg='do not traverse into string if not `traverse_string`')
+        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', 0),
+                                      _traverse_string=True), 's',
+                         msg='traverse into string if `traverse_string`')
+        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, (1.2, 1),
+                                      _traverse_string=True), '.',
+                         msg='traverse into converted data if `traverse_string`')
+        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', Ellipsis),
+                                      _traverse_string=True), 'str',
+                         msg='`...` should result in string (same value) if `traverse_string`')
+        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', slice(0, None, 2)),
+                                      _traverse_string=True), 'sr',
+                         msg='`slice` should result in string if `traverse_string`')
+        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', lambda i, v: i or v == 's'),
+                                      _traverse_string=True), 'str',
+                         msg='function should result in string if `traverse_string`')
+        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', (0, 2)),
+                                      _traverse_string=True), ['s', 'r'],
+                         msg='branching should result in list if `traverse_string`')
+        self.assertEqual(traverse_obj({}, (0, Ellipsis), _traverse_string=True), [],
+                         msg='branching should result in list if `traverse_string`')
+        self.assertEqual(traverse_obj({}, (0, lambda x, y: True), _traverse_string=True), [],
+                         msg='branching should result in list if `traverse_string`')
+        self.assertEqual(traverse_obj({}, (0, slice(1)), _traverse_string=True), [],
+                         msg='branching should result in list if `traverse_string`')
+
+        # Test re.Match as input obj
+        mobj = re.match(r'^0(12)(?P<group>3)(4)?$', '0123')
+        self.assertEqual(traverse_obj(mobj, Ellipsis), [x for x in mobj.groups() if x is not None],
+                         msg='`...` on a `re.Match` should give its `groups()`')
+        self.assertEqual(traverse_obj(mobj, lambda k, _: k in (0, 2)), ['0123', '3'],
+                         msg='function on a `re.Match` should give groupno, value starting at 0')
+        self.assertEqual(traverse_obj(mobj, 'group'), '3',
+                         msg='str key on a `re.Match` should give group with that name')
+        self.assertEqual(traverse_obj(mobj, 2), '3',
+                         msg='int key on a `re.Match` should give group with that name')
+        self.assertEqual(traverse_obj(mobj, 'gRoUp', casesense=False), '3',
+                         msg='str key on a `re.Match` should respect casesense')
+        self.assertEqual(traverse_obj(mobj, 'fail'), None,
+                         msg='failing str key on a `re.Match` should return `default`')
+        self.assertEqual(traverse_obj(mobj, 'gRoUpS', casesense=False), None,
+                         msg='failing str key on a `re.Match` should return `default`')
+        self.assertEqual(traverse_obj(mobj, 8), None,
+                         msg='failing int key on a `re.Match` should return `default`')
+        self.assertEqual(traverse_obj(mobj, lambda k, _: k in (0, 'group')), ['0123', '3'],
+                         msg='function on a `re.Match` should give group name as well')
+
+        # Test xml.etree.ElementTree.Element as input obj
+        etree = compat_etree_fromstring('''<?xml version="1.0"?>
+        <data>
+            <country name="Liechtenstein">
+                <rank>1</rank>
+                <year>2008</year>
+                <gdppc>141100</gdppc>
+                <neighbor name="Austria" direction="E"/>
+                <neighbor name="Switzerland" direction="W"/>
+            </country>
+            <country name="Singapore">
+                <rank>4</rank>
+                <year>2011</year>
+                <gdppc>59900</gdppc>
+                <neighbor name="Malaysia" direction="N"/>
+            </country>
+            <country name="Panama">
+                <rank>68</rank>
+                <year>2011</year>
+                <gdppc>13600</gdppc>
+                <neighbor name="Costa Rica" direction="W"/>
+                <neighbor name="Colombia" direction="E"/>
+            </country>
+        </data>''')
+        self.assertEqual(traverse_obj(etree, ''), etree,
+                         msg='empty str key should return the element itself')
+        self.assertEqual(traverse_obj(etree, 'country'), list(etree),
+                         msg='str key should return all children with that tag name')
+        self.assertEqual(traverse_obj(etree, Ellipsis), list(etree),
+                         msg='`...` as key should return all children')
+        self.assertEqual(traverse_obj(etree, lambda _, x: x[0].text == '4'), [etree[1]],
+                         msg='function as key should get element as value')
+        self.assertEqual(traverse_obj(etree, lambda i, _: i == 1), [etree[1]],
+                         msg='function as key should get index as key')
+        self.assertEqual(traverse_obj(etree, 0), etree[0],
+                         msg='int key should return the nth child')
+        self.assertEqual(traverse_obj(etree, './/neighbor/@name'),
+                         ['Austria', 'Switzerland', 'Malaysia', 'Costa Rica', 'Colombia'],
+                         msg='`@<attribute>` at end of path should give that attribute')
+        self.assertEqual(traverse_obj(etree, '//neighbor/@fail'), [None, None, None, None, None],
+                         msg='`@<nonexistent>` at end of path should give `None`')
+        self.assertEqual(traverse_obj(etree, ('//neighbor/@', 2)), {'name': 'Malaysia', 'direction': 'N'},
+                         msg='`@` should give the full attribute dict')
+        self.assertEqual(traverse_obj(etree, '//year/text()'), ['2008', '2011', '2011'],
+                         msg='`text()` at end of path should give the inner text')
+        self.assertEqual(traverse_obj(etree, '//*[@direction]/@direction'), ['E', 'W', 'N', 'W', 'E'],
+                         msg='full python xpath features should be supported')
+        self.assertEqual(traverse_obj(etree, (0, '@name')), 'Liechtenstein',
+                         msg='special transformations should act on current element')
+        self.assertEqual(traverse_obj(etree, ('country', 0, Ellipsis, 'text()', T(int_or_none))), [1, 2008, 141100],
+                         msg='special transformations should act on current element')
+
+    def test_traversal_unbranching(self):
+        self.assertEqual(traverse_obj(_TEST_DATA, [(100, 1.2), all]), [100, 1.2],
+                         msg='`all` should give all results as list')
+        self.assertEqual(traverse_obj(_TEST_DATA, [(100, 1.2), any]), 100,
+                         msg='`any` should give the first result')
+        self.assertEqual(traverse_obj(_TEST_DATA, [100, all]), [100],
+                         msg='`all` should give list if non branching')
+        self.assertEqual(traverse_obj(_TEST_DATA, [100, any]), 100,
+                         msg='`any` should give single item if non branching')
+        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 100), all]), [100],
+                         msg='`all` should filter `None` and empty dict')
+        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 100), any]), 100,
+                         msg='`any` should filter `None` and empty dict')
+        self.assertEqual(traverse_obj(_TEST_DATA, [{
+            'all': [('dict', 'None', 100, 1.2), all],
+            'any': [('dict', 'None', 100, 1.2), any],
+        }]), {'all': [100, 1.2], 'any': 100},
+            msg='`all`/`any` should apply to each dict path separately')
+        self.assertEqual(traverse_obj(_TEST_DATA, [{
+            'all': [('dict', 'None', 100, 1.2), all],
+            'any': [('dict', 'None', 100, 1.2), any],
+        }], get_all=False), {'all': [100, 1.2], 'any': 100},
+            msg='`all`/`any` should apply to dict regardless of `get_all`')
+        self.assertIs(traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), all, T(float)]), None,
+                      msg='`all` should reset branching status')
+        self.assertIs(traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), any, T(float)]), None,
+                      msg='`any` should reset branching status')
+        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), all, Ellipsis, T(float)]), [1.2],
+                         msg='`all` should allow further branching')
+        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 'urls', 'data'), any, Ellipsis, 'index']), [0, 1],
+                         msg='`any` should allow further branching')
+
+    def test_traversal_morsel(self):
+        values = {
+            'expires': 'a',
+            'path': 'b',
+            'comment': 'c',
+            'domain': 'd',
+            'max-age': 'e',
+            'secure': 'f',
+            'httponly': 'g',
+            'version': 'h',
+            'samesite': 'i',
+        }
+        # SameSite added in Py3.8, breaks .update for 3.5-3.7
+        if sys.version_info < (3, 8):
+            del values['samesite']
+        morsel = compat_http_cookies.Morsel()
+        morsel.set(str('item_key'), 'item_value', 'coded_value')
+        morsel.update(values)
+        values['key'] = str('item_key')
+        values['value'] = 'item_value'
+        values = dict((str(k), v) for k, v in values.items())
+        # make test pass even without ordered dict
+        value_set = set(values.values())
+
+        for key, value in values.items():
+            self.assertEqual(traverse_obj(morsel, key), value,
+                             msg='Morsel should provide access to all values')
+        self.assertEqual(set(traverse_obj(morsel, Ellipsis)), value_set,
+                         msg='`...` should yield all values')
+        self.assertEqual(set(traverse_obj(morsel, lambda k, v: True)), value_set,
+                         msg='function key should yield all values')
+        self.assertIs(traverse_obj(morsel, [(None,), any]), morsel,
+                      msg='Morsel should not be implicitly changed to dict on usage')
+
+    def test_get_first(self):
+        self.assertEqual(get_first([{'a': None}, {'a': 'spam'}], 'a'), 'spam')
+
+    def test_dict_get(self):
+        FALSE_VALUES = {
+            'none': None,
+            'false': False,
+            'zero': 0,
+            'empty_string': '',
+            'empty_list': [],
+        }
+        d = FALSE_VALUES.copy()
+        d['a'] = 42
+        self.assertEqual(dict_get(d, 'a'), 42)
+        self.assertEqual(dict_get(d, 'b'), None)
+        self.assertEqual(dict_get(d, 'b', 42), 42)
+        self.assertEqual(dict_get(d, ('a', )), 42)
+        self.assertEqual(dict_get(d, ('b', 'a', )), 42)
+        self.assertEqual(dict_get(d, ('b', 'c', 'a', 'd', )), 42)
+        self.assertEqual(dict_get(d, ('b', 'c', )), None)
+        self.assertEqual(dict_get(d, ('b', 'c', ), 42), 42)
+        for key, false_value in FALSE_VALUES.items():
+            self.assertEqual(dict_get(d, ('b', 'c', key, )), None)
+            self.assertEqual(dict_get(d, ('b', 'c', key, ), skip_false_values=False), false_value)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/test/test_utils.py b/test/test_utils.py
index 179d21cf5..de7fe80b8 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -14,7 +14,6 @@ sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 import io
 import itertools
 import json
-import re
 import xml.etree.ElementTree
 
 from youtube_dl.utils import (
@@ -28,7 +27,6 @@ from youtube_dl.utils import (
     DateRange,
     detect_exe_version,
     determine_ext,
-    dict_get,
     encode_base_n,
     encode_compat_str,
     encodeFilename,
@@ -44,7 +42,6 @@ from youtube_dl.utils import (
     get_element_by_attribute,
     get_elements_by_class,
     get_elements_by_attribute,
-    get_first,
     InAdvancePagedList,
     int_or_none,
     intlist_to_bytes,
@@ -84,14 +81,11 @@ from youtube_dl.utils import (
     sanitized_Request,
     shell_quote,
     smuggle_url,
-    str_or_none,
     str_to_int,
     strip_jsonp,
     strip_or_none,
     subtitles_filename,
-    T,
     timeconvert,
-    traverse_obj,
     try_call,
     unescapeHTML,
     unified_strdate,
@@ -123,7 +117,6 @@ from youtube_dl.compat import (
     compat_chr,
     compat_etree_fromstring,
     compat_getenv,
-    compat_http_cookies,
     compat_os_name,
     compat_setenv,
     compat_str,
@@ -1685,481 +1678,5 @@ Line 1
             from_dict={'a': 'c', 'c': [], 'b': 'd', 'd': None}), 'c-d')
 
 
-class TestTraversal(unittest.TestCase):
-    str = compat_str
-    _TEST_DATA = {
-        100: 100,
-        1.2: 1.2,
-        'str': 'str',
-        'None': None,
-        '...': Ellipsis,
-        'urls': [
-            {'index': 0, 'url': 'https://www.example.com/0'},
-            {'index': 1, 'url': 'https://www.example.com/1'},
-        ],
-        'data': (
-            {'index': 2},
-            {'index': 3},
-        ),
-        'dict': {},
-    }
-
-    # yt-dlp shim
-    def assertCountEqual(self, expected, got, msg='count should be the same'):
-        return self.assertEqual(len(tuple(expected)), len(tuple(got)), msg=msg)
-
-    def assertMaybeCountEqual(self, *args, **kwargs):
-        if sys.version_info < (3, 7):
-            # random dict order
-            return self.assertCountEqual(*args, **kwargs)
-        else:
-            return self.assertEqual(*args, **kwargs)
-
-    def test_traverse_obj(self):
-        str = self.str
-        _TEST_DATA = self._TEST_DATA
-
-        # define a pukka Iterable
-        def iter_range(stop):
-            for from_ in range(stop):
-                yield from_
-
-        # Test base functionality
-        self.assertEqual(traverse_obj(_TEST_DATA, ('str',)), 'str',
-                         msg='allow tuple path')
-        self.assertEqual(traverse_obj(_TEST_DATA, ['str']), 'str',
-                         msg='allow list path')
-        self.assertEqual(traverse_obj(_TEST_DATA, (value for value in ("str",))), 'str',
-                         msg='allow iterable path')
-        self.assertEqual(traverse_obj(_TEST_DATA, 'str'), 'str',
-                         msg='single items should be treated as a path')
-        self.assertEqual(traverse_obj(_TEST_DATA, None), _TEST_DATA)
-        self.assertEqual(traverse_obj(_TEST_DATA, 100), 100)
-        self.assertEqual(traverse_obj(_TEST_DATA, 1.2), 1.2)
-
-        # Test Ellipsis behavior
-        self.assertCountEqual(traverse_obj(_TEST_DATA, Ellipsis),
-                              (item for item in _TEST_DATA.values() if item not in (None, {})),
-                              msg='`...` should give all non-discarded values')
-        self.assertCountEqual(traverse_obj(_TEST_DATA, ('urls', 0, Ellipsis)), _TEST_DATA['urls'][0].values(),
-                              msg='`...` selection for dicts should select all values')
-        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, Ellipsis, 'url')),
-                         ['https://www.example.com/0', 'https://www.example.com/1'],
-                         msg='nested `...` queries should work')
-        self.assertCountEqual(traverse_obj(_TEST_DATA, (Ellipsis, Ellipsis, 'index')), iter_range(4),
-                              msg='`...` query result should be flattened')
-        self.assertEqual(traverse_obj(iter(range(4)), Ellipsis), list(range(4)),
-                         msg='`...` should accept iterables')
-
-        # Test function as key
-        self.assertEqual(traverse_obj(_TEST_DATA, lambda x, y: x == 'urls' and isinstance(y, list)),
-                         [_TEST_DATA['urls']],
-                         msg='function as query key should perform a filter based on (key, value)')
-        self.assertCountEqual(traverse_obj(_TEST_DATA, lambda _, x: isinstance(x[0], str)), set(('str',)),
-                              msg='exceptions in the query function should be caught')
-        self.assertEqual(traverse_obj(iter(range(4)), lambda _, x: x % 2 == 0), [0, 2],
-                         msg='function key should accept iterables')
-        if __debug__:
-            with self.assertRaises(Exception, msg='Wrong function signature should raise in debug'):
-                traverse_obj(_TEST_DATA, lambda a: Ellipsis)
-            with self.assertRaises(Exception, msg='Wrong function signature should raise in debug'):
-                traverse_obj(_TEST_DATA, lambda a, b, c: Ellipsis)
-
-        # Test set as key (transformation/type, like `expected_type`)
-        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str.upper), )), ['STR'],
-                         msg='Function in set should be a transformation')
-        self.assertEqual(traverse_obj(_TEST_DATA, ('fail', T(lambda _: 'const'))), 'const',
-                         msg='Function in set should always be called')
-        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str))), ['str'],
-                         msg='Type in set should be a type filter')
-        self.assertMaybeCountEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str, int))), [100, 'str'],
-                                   msg='Multiple types in set should be a type filter')
-        self.assertEqual(traverse_obj(_TEST_DATA, T(dict)), _TEST_DATA,
-                         msg='A single set should be wrapped into a path')
-        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str.upper))), ['STR'],
-                         msg='Transformation function should not raise')
-        self.assertMaybeCountEqual(traverse_obj(_TEST_DATA, (Ellipsis, T(str_or_none))),
-                                   [item for item in map(str_or_none, _TEST_DATA.values()) if item is not None],
-                                   msg='Function in set should be a transformation')
-        if __debug__:
-            with self.assertRaises(Exception, msg='Sets with length != 1 should raise in debug'):
-                traverse_obj(_TEST_DATA, set())
-            with self.assertRaises(Exception, msg='Sets with length != 1 should raise in debug'):
-                traverse_obj(_TEST_DATA, set((str.upper, str)))
-
-        # Test `slice` as a key
-        _SLICE_DATA = [0, 1, 2, 3, 4]
-        self.assertEqual(traverse_obj(_TEST_DATA, ('dict', slice(1))), None,
-                         msg='slice on a dictionary should not throw')
-        self.assertEqual(traverse_obj(_SLICE_DATA, slice(1)), _SLICE_DATA[:1],
-                         msg='slice key should apply slice to sequence')
-        self.assertEqual(traverse_obj(_SLICE_DATA, slice(1, 2)), _SLICE_DATA[1:2],
-                         msg='slice key should apply slice to sequence')
-        self.assertEqual(traverse_obj(_SLICE_DATA, slice(1, 4, 2)), _SLICE_DATA[1:4:2],
-                         msg='slice key should apply slice to sequence')
-
-        # Test alternative paths
-        self.assertEqual(traverse_obj(_TEST_DATA, 'fail', 'str'), 'str',
-                         msg='multiple `paths` should be treated as alternative paths')
-        self.assertEqual(traverse_obj(_TEST_DATA, 'str', 100), 'str',
-                         msg='alternatives should exit early')
-        self.assertEqual(traverse_obj(_TEST_DATA, 'fail', 'fail'), None,
-                         msg='alternatives should return `default` if exhausted')
-        self.assertEqual(traverse_obj(_TEST_DATA, (Ellipsis, 'fail'), 100), 100,
-                         msg='alternatives should track their own branching return')
-        self.assertEqual(traverse_obj(_TEST_DATA, ('dict', Ellipsis), ('data', Ellipsis)), list(_TEST_DATA['data']),
-                         msg='alternatives on empty objects should search further')
-
-        # Test branch and path nesting
-        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', (3, 0), 'url')), ['https://www.example.com/0'],
-                         msg='tuple as key should be treated as branches')
-        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', [3, 0], 'url')), ['https://www.example.com/0'],
-                         msg='list as key should be treated as branches')
-        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', ((1, 'fail'), (0, 'url')))), ['https://www.example.com/0'],
-                         msg='double nesting in path should be treated as paths')
-        self.assertEqual(traverse_obj(['0', [1, 2]], [(0, 1), 0]), [1],
-                         msg='do not fail early on branching')
-        self.assertCountEqual(traverse_obj(_TEST_DATA, ('urls', ((1, ('fail', 'url')), (0, 'url')))),
-                              ['https://www.example.com/0', 'https://www.example.com/1'],
-                              msg='triple nesting in path should be treated as branches')
-        self.assertEqual(traverse_obj(_TEST_DATA, ('urls', ('fail', (Ellipsis, 'url')))),
-                         ['https://www.example.com/0', 'https://www.example.com/1'],
-                         msg='ellipsis as branch path start gets flattened')
-
-        # Test dictionary as key
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: 100, 1: 1.2}), {0: 100, 1: 1.2},
-                         msg='dict key should result in a dict with the same keys')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', 0, 'url')}),
-                         {0: 'https://www.example.com/0'},
-                         msg='dict key should allow paths')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', (3, 0), 'url')}),
-                         {0: ['https://www.example.com/0']},
-                         msg='tuple in dict path should be treated as branches')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', ((1, 'fail'), (0, 'url')))}),
-                         {0: ['https://www.example.com/0']},
-                         msg='double nesting in dict path should be treated as paths')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', ((1, ('fail', 'url')), (0, 'url')))}),
-                         {0: ['https://www.example.com/1', 'https://www.example.com/0']},
-                         msg='triple nesting in dict path should be treated as branches')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'fail'}), {},
-                         msg='remove `None` values when top level dict key fails')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'fail'}, default=Ellipsis), {0: Ellipsis},
-                         msg='use `default` if key fails and `default`')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'dict'}), {},
-                         msg='remove empty values when dict key')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'dict'}, default=Ellipsis), {0: Ellipsis},
-                         msg='use `default` when dict key and a default')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: {0: 'fail'}}), {},
-                         msg='remove empty values when nested dict key fails')
-        self.assertEqual(traverse_obj(None, {0: 'fail'}), {},
-                         msg='default to dict if pruned')
-        self.assertEqual(traverse_obj(None, {0: 'fail'}, default=Ellipsis), {0: Ellipsis},
-                         msg='default to dict if pruned and default is given')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: {0: 'fail'}}, default=Ellipsis), {0: {0: Ellipsis}},
-                         msg='use nested `default` when nested dict key fails and `default`')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('dict', Ellipsis)}), {},
-                         msg='remove key if branch in dict key not successful')
-
-        # Testing default parameter behavior
-        _DEFAULT_DATA = {'None': None, 'int': 0, 'list': []}
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'fail'), None,
-                         msg='default value should be `None`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'fail', 'fail', default=Ellipsis), Ellipsis,
-                         msg='chained fails should result in default')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'None', 'int'), 0,
-                         msg='should not short cirquit on `None`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'fail', default=1), 1,
-                         msg='invalid dict key should result in `default`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, 'None', default=1), 1,
-                         msg='`None` is a deliberate sentinel and should become `default`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, ('list', 10)), None,
-                         msg='`IndexError` should result in `default`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, (Ellipsis, 'fail'), default=1), 1,
-                         msg='if branched but not successful return `default` if defined, not `[]`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, (Ellipsis, 'fail'), default=None), None,
-                         msg='if branched but not successful return `default` even if `default` is `None`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, (Ellipsis, 'fail')), [],
-                         msg='if branched but not successful return `[]`, not `default`')
-        self.assertEqual(traverse_obj(_DEFAULT_DATA, ('list', Ellipsis)), [],
-                         msg='if branched but object is empty return `[]`, not `default`')
-        self.assertEqual(traverse_obj(None, Ellipsis), [],
-                         msg='if branched but object is `None` return `[]`, not `default`')
-        self.assertEqual(traverse_obj({0: None}, (0, Ellipsis)), [],
-                         msg='if branched but state is `None` return `[]`, not `default`')
-
-        branching_paths = [
-            ('fail', Ellipsis),
-            (Ellipsis, 'fail'),
-            100 * ('fail',) + (Ellipsis,),
-            (Ellipsis,) + 100 * ('fail',),
-        ]
-        for branching_path in branching_paths:
-            self.assertEqual(traverse_obj({}, branching_path), [],
-                             msg='if branched but state is `None`, return `[]` (not `default`)')
-            self.assertEqual(traverse_obj({}, 'fail', branching_path), [],
-                             msg='if branching in last alternative and previous did not match, return `[]` (not `default`)')
-            self.assertEqual(traverse_obj({0: 'x'}, 0, branching_path), 'x',
-                             msg='if branching in last alternative and previous did match, return single value')
-            self.assertEqual(traverse_obj({0: 'x'}, branching_path, 0), 'x',
-                             msg='if branching in first alternative and non-branching path does match, return single value')
-            self.assertEqual(traverse_obj({}, branching_path, 'fail'), None,
-                             msg='if branching in first alternative and non-branching path does not match, return `default`')
-
-        # Testing expected_type behavior
-        _EXPECTED_TYPE_DATA = {'str': 'str', 'int': 0}
-        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=str),
-                         'str', msg='accept matching `expected_type` type')
-        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=int),
-                         None, msg='reject non-matching `expected_type` type')
-        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'int', expected_type=lambda x: str(x)),
-                         '0', msg='transform type using type function')
-        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=lambda _: 1 / 0),
-                         None, msg='wrap expected_type function in try_call')
-        self.assertEqual(traverse_obj(_EXPECTED_TYPE_DATA, Ellipsis, expected_type=str),
-                         ['str'], msg='eliminate items that expected_type fails on')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: 100, 1: 1.2}, expected_type=int),
-                         {0: 100}, msg='type as expected_type should filter dict values')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: 100, 1: 1.2, 2: 'None'}, expected_type=str_or_none),
-                         {0: '100', 1: '1.2'}, msg='function as expected_type should transform dict values')
-        self.assertEqual(traverse_obj(_TEST_DATA, ({0: 1.2}, 0, set((int_or_none,))), expected_type=int),
-                         1, msg='expected_type should not filter non-final dict values')
-        self.assertEqual(traverse_obj(_TEST_DATA, {0: {0: 100, 1: 'str'}}, expected_type=int),
-                         {0: {0: 100}}, msg='expected_type should transform deep dict values')
-        self.assertEqual(traverse_obj(_TEST_DATA, [({0: '...'}, {0: '...'})], expected_type=type(Ellipsis)),
-                         [{0: Ellipsis}, {0: Ellipsis}], msg='expected_type should transform branched dict values')
-        self.assertEqual(traverse_obj({1: {3: 4}}, [(1, 2), 3], expected_type=int),
-                         [4], msg='expected_type regression for type matching in tuple branching')
-        self.assertEqual(traverse_obj(_TEST_DATA, ['data', Ellipsis], expected_type=int),
-                         [], msg='expected_type regression for type matching in dict result')
-
-        # Test get_all behavior
-        _GET_ALL_DATA = {'key': [0, 1, 2]}
-        self.assertEqual(traverse_obj(_GET_ALL_DATA, ('key', Ellipsis), get_all=False), 0,
-                         msg='if not `get_all`, return only first matching value')
-        self.assertEqual(traverse_obj(_GET_ALL_DATA, Ellipsis, get_all=False), [0, 1, 2],
-                         msg='do not overflatten if not `get_all`')
-
-        # Test casesense behavior
-        _CASESENSE_DATA = {
-            'KeY': 'value0',
-            0: {
-                'KeY': 'value1',
-                0: {'KeY': 'value2'},
-            },
-            # FULLWIDTH LATIN CAPITAL LETTER K
-            '\uff2bey': 'value3',
-        }
-        self.assertEqual(traverse_obj(_CASESENSE_DATA, 'key'), None,
-                         msg='dict keys should be case sensitive unless `casesense`')
-        self.assertEqual(traverse_obj(_CASESENSE_DATA, 'keY',
-                                      casesense=False), 'value0',
-                         msg='allow non matching key case if `casesense`')
-        self.assertEqual(traverse_obj(_CASESENSE_DATA, '\uff4bey',  # FULLWIDTH LATIN SMALL LETTER K
-                                      casesense=False), 'value3',
-                         msg='allow non matching Unicode key case if `casesense`')
-        self.assertEqual(traverse_obj(_CASESENSE_DATA, (0, ('keY',)),
-                                      casesense=False), ['value1'],
-                         msg='allow non matching key case in branch if `casesense`')
-        self.assertEqual(traverse_obj(_CASESENSE_DATA, (0, ((0, 'keY'),)),
-                                      casesense=False), ['value2'],
-                         msg='allow non matching key case in branch path if `casesense`')
-
-        # Test traverse_string behavior
-        _TRAVERSE_STRING_DATA = {'str': 'str', 1.2: 1.2}
-        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', 0)), None,
-                         msg='do not traverse into string if not `traverse_string`')
-        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', 0),
-                                      _traverse_string=True), 's',
-                         msg='traverse into string if `traverse_string`')
-        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, (1.2, 1),
-                                      _traverse_string=True), '.',
-                         msg='traverse into converted data if `traverse_string`')
-        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', Ellipsis),
-                                      _traverse_string=True), 'str',
-                         msg='`...` should result in string (same value) if `traverse_string`')
-        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', slice(0, None, 2)),
-                                      _traverse_string=True), 'sr',
-                         msg='`slice` should result in string if `traverse_string`')
-        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', lambda i, v: i or v == 's'),
-                                      _traverse_string=True), 'str',
-                         msg='function should result in string if `traverse_string`')
-        self.assertEqual(traverse_obj(_TRAVERSE_STRING_DATA, ('str', (0, 2)),
-                                      _traverse_string=True), ['s', 'r'],
-                         msg='branching should result in list if `traverse_string`')
-        self.assertEqual(traverse_obj({}, (0, Ellipsis), _traverse_string=True), [],
-                         msg='branching should result in list if `traverse_string`')
-        self.assertEqual(traverse_obj({}, (0, lambda x, y: True), _traverse_string=True), [],
-                         msg='branching should result in list if `traverse_string`')
-        self.assertEqual(traverse_obj({}, (0, slice(1)), _traverse_string=True), [],
-                         msg='branching should result in list if `traverse_string`')
-
-        # Test re.Match as input obj
-        mobj = re.match(r'^0(12)(?P<group>3)(4)?$', '0123')
-        self.assertEqual(traverse_obj(mobj, Ellipsis), [x for x in mobj.groups() if x is not None],
-                         msg='`...` on a `re.Match` should give its `groups()`')
-        self.assertEqual(traverse_obj(mobj, lambda k, _: k in (0, 2)), ['0123', '3'],
-                         msg='function on a `re.Match` should give groupno, value starting at 0')
-        self.assertEqual(traverse_obj(mobj, 'group'), '3',
-                         msg='str key on a `re.Match` should give group with that name')
-        self.assertEqual(traverse_obj(mobj, 2), '3',
-                         msg='int key on a `re.Match` should give group with that name')
-        self.assertEqual(traverse_obj(mobj, 'gRoUp', casesense=False), '3',
-                         msg='str key on a `re.Match` should respect casesense')
-        self.assertEqual(traverse_obj(mobj, 'fail'), None,
-                         msg='failing str key on a `re.Match` should return `default`')
-        self.assertEqual(traverse_obj(mobj, 'gRoUpS', casesense=False), None,
-                         msg='failing str key on a `re.Match` should return `default`')
-        self.assertEqual(traverse_obj(mobj, 8), None,
-                         msg='failing int key on a `re.Match` should return `default`')
-        self.assertEqual(traverse_obj(mobj, lambda k, _: k in (0, 'group')), ['0123', '3'],
-                         msg='function on a `re.Match` should give group name as well')
-
-        # Test xml.etree.ElementTree.Element as input obj
-        etree = compat_etree_fromstring('''<?xml version="1.0"?>
-        <data>
-            <country name="Liechtenstein">
-                <rank>1</rank>
-                <year>2008</year>
-                <gdppc>141100</gdppc>
-                <neighbor name="Austria" direction="E"/>
-                <neighbor name="Switzerland" direction="W"/>
-            </country>
-            <country name="Singapore">
-                <rank>4</rank>
-                <year>2011</year>
-                <gdppc>59900</gdppc>
-                <neighbor name="Malaysia" direction="N"/>
-            </country>
-            <country name="Panama">
-                <rank>68</rank>
-                <year>2011</year>
-                <gdppc>13600</gdppc>
-                <neighbor name="Costa Rica" direction="W"/>
-                <neighbor name="Colombia" direction="E"/>
-            </country>
-        </data>''')
-        self.assertEqual(traverse_obj(etree, ''), etree,
-                         msg='empty str key should return the element itself')
-        self.assertEqual(traverse_obj(etree, 'country'), list(etree),
-                         msg='str key should return all children with that tag name')
-        self.assertEqual(traverse_obj(etree, Ellipsis), list(etree),
-                         msg='`...` as key should return all children')
-        self.assertEqual(traverse_obj(etree, lambda _, x: x[0].text == '4'), [etree[1]],
-                         msg='function as key should get element as value')
-        self.assertEqual(traverse_obj(etree, lambda i, _: i == 1), [etree[1]],
-                         msg='function as key should get index as key')
-        self.assertEqual(traverse_obj(etree, 0), etree[0],
-                         msg='int key should return the nth child')
-        self.assertEqual(traverse_obj(etree, './/neighbor/@name'),
-                         ['Austria', 'Switzerland', 'Malaysia', 'Costa Rica', 'Colombia'],
-                         msg='`@<attribute>` at end of path should give that attribute')
-        self.assertEqual(traverse_obj(etree, '//neighbor/@fail'), [None, None, None, None, None],
-                         msg='`@<nonexistent>` at end of path should give `None`')
-        self.assertEqual(traverse_obj(etree, ('//neighbor/@', 2)), {'name': 'Malaysia', 'direction': 'N'},
-                         msg='`@` should give the full attribute dict')
-        self.assertEqual(traverse_obj(etree, '//year/text()'), ['2008', '2011', '2011'],
-                         msg='`text()` at end of path should give the inner text')
-        self.assertEqual(traverse_obj(etree, '//*[@direction]/@direction'), ['E', 'W', 'N', 'W', 'E'],
-                         msg='full python xpath features should be supported')
-        self.assertEqual(traverse_obj(etree, (0, '@name')), 'Liechtenstein',
-                         msg='special transformations should act on current element')
-        self.assertEqual(traverse_obj(etree, ('country', 0, Ellipsis, 'text()', T(int_or_none))), [1, 2008, 141100],
-                         msg='special transformations should act on current element')
-
-    def test_traversal_unbranching(self):
-        # str = self.str
-        _TEST_DATA = self._TEST_DATA
-
-        self.assertEqual(traverse_obj(_TEST_DATA, [(100, 1.2), all]), [100, 1.2],
-                         msg='`all` should give all results as list')
-        self.assertEqual(traverse_obj(_TEST_DATA, [(100, 1.2), any]), 100,
-                         msg='`any` should give the first result')
-        self.assertEqual(traverse_obj(_TEST_DATA, [100, all]), [100],
-                         msg='`all` should give list if non branching')
-        self.assertEqual(traverse_obj(_TEST_DATA, [100, any]), 100,
-                         msg='`any` should give single item if non branching')
-        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 100), all]), [100],
-                         msg='`all` should filter `None` and empty dict')
-        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 100), any]), 100,
-                         msg='`any` should filter `None` and empty dict')
-        self.assertEqual(traverse_obj(_TEST_DATA, [{
-            'all': [('dict', 'None', 100, 1.2), all],
-            'any': [('dict', 'None', 100, 1.2), any],
-        }]), {'all': [100, 1.2], 'any': 100},
-            msg='`all`/`any` should apply to each dict path separately')
-        self.assertEqual(traverse_obj(_TEST_DATA, [{
-            'all': [('dict', 'None', 100, 1.2), all],
-            'any': [('dict', 'None', 100, 1.2), any],
-        }], get_all=False), {'all': [100, 1.2], 'any': 100},
-            msg='`all`/`any` should apply to dict regardless of `get_all`')
-        self.assertIs(traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), all, T(float)]), None,
-                      msg='`all` should reset branching status')
-        self.assertIs(traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), any, T(float)]), None,
-                      msg='`any` should reset branching status')
-        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), all, Ellipsis, T(float)]), [1.2],
-                         msg='`all` should allow further branching')
-        self.assertEqual(traverse_obj(_TEST_DATA, [('dict', 'None', 'urls', 'data'), any, Ellipsis, 'index']), [0, 1],
-                         msg='`any` should allow further branching')
-
-    def test_traversal_morsel(self):
-        values = {
-            'expires': 'a',
-            'path': 'b',
-            'comment': 'c',
-            'domain': 'd',
-            'max-age': 'e',
-            'secure': 'f',
-            'httponly': 'g',
-            'version': 'h',
-            'samesite': 'i',
-        }
-        # SameSite added in Py3.8, breaks .update for 3.5-3.7
-        if sys.version_info < (3, 8):
-            del values['samesite']
-        morsel = compat_http_cookies.Morsel()
-        morsel.set(str('item_key'), 'item_value', 'coded_value')
-        morsel.update(values)
-        values['key'] = str('item_key')
-        values['value'] = 'item_value'
-        values = dict((str(k), v) for k, v in values.items())
-        # make test pass even without ordered dict
-        value_set = set(values.values())
-
-        for key, value in values.items():
-            self.assertEqual(traverse_obj(morsel, key), value,
-                             msg='Morsel should provide access to all values')
-        self.assertEqual(set(traverse_obj(morsel, Ellipsis)), value_set,
-                         msg='`...` should yield all values')
-        self.assertEqual(set(traverse_obj(morsel, lambda k, v: True)), value_set,
-                         msg='function key should yield all values')
-        self.assertIs(traverse_obj(morsel, [(None,), any]), morsel,
-                      msg='Morsel should not be implicitly changed to dict on usage')
-
-    def test_get_first(self):
-        self.assertEqual(get_first([{'a': None}, {'a': 'spam'}], 'a'), 'spam')
-
-    def test_dict_get(self):
-        FALSE_VALUES = {
-            'none': None,
-            'false': False,
-            'zero': 0,
-            'empty_string': '',
-            'empty_list': [],
-        }
-        d = FALSE_VALUES.copy()
-        d['a'] = 42
-        self.assertEqual(dict_get(d, 'a'), 42)
-        self.assertEqual(dict_get(d, 'b'), None)
-        self.assertEqual(dict_get(d, 'b', 42), 42)
-        self.assertEqual(dict_get(d, ('a', )), 42)
-        self.assertEqual(dict_get(d, ('b', 'a', )), 42)
-        self.assertEqual(dict_get(d, ('b', 'c', 'a', 'd', )), 42)
-        self.assertEqual(dict_get(d, ('b', 'c', )), None)
-        self.assertEqual(dict_get(d, ('b', 'c', ), 42), 42)
-        for key, false_value in FALSE_VALUES.items():
-            self.assertEqual(dict_get(d, ('b', 'c', key, )), None)
-            self.assertEqual(dict_get(d, ('b', 'c', key, ), skip_false_values=False), false_value)
-
-
 if __name__ == '__main__':
     unittest.main()
diff --git a/youtube_dl/traversal.py b/youtube_dl/traversal.py
new file mode 100644
index 000000000..834cfef7f
--- /dev/null
+++ b/youtube_dl/traversal.py
@@ -0,0 +1,10 @@
+# coding: utf-8
+
+# TODO: move these utils.fns here and move import to utils
+# flake8: noqa
+from .utils import (
+    dict_get,
+    get_first,
+    T,
+    traverse_obj,
+)