Allow entire infodict to be printed using %()s

Makes `--dump-json` redundant

README.md

@@ -919,7 +919,7 @@ # OUTPUT TEMPLATE
 It may however also contain special sequences that will be replaced when downloading each video. The special sequences may be formatted according to [python string formatting operations](https://docs.python.org/2/library/stdtypes.html#string-formatting). For example, `%(NAME)s` or `%(NAME)05d`. To clarify, that is a percent symbol followed by a name in parentheses, followed by formatting operations.
 
 The field names themselves (the part inside the parenthesis) can also have some special formatting:
-1. **Object traversal**: The dictionaries and lists available in metadata can be traversed by using a `.` (dot) separator. You can also do python slicing using `:`. Eg: `%(tags.0)s`, `%(subtitles.en.-1.ext)`, `%(id.3:7:-1)s`, `%(formats.:.format_id)s`. Note that all the fields that become available using this method are not listed below. Use `-j` to see such fields
+1. **Object traversal**: The dictionaries and lists available in metadata can be traversed by using a `.` (dot) separator. You can also do python slicing using `:`. Eg: `%(tags.0)s`, `%(subtitles.en.-1.ext)s`, `%(id.3:7:-1)s`, `%(formats.:.format_id)s`. `%()s` refers to the entire infodict. Note that all the fields that become available using this method are not listed below. Use `-j` to see such fields
 1. **Addition**: Addition and subtraction of numeric fields can be done using `+` and `-` respectively. Eg: `%(playlist_index+10)03d`, `%(n_entries+1-playlist_index)d`
 1. **Date/time Formatting**: Date/time fields can be formatted according to [strftime formatting](https://docs.python.org/3/library/datetime.html#strftime-and-strptime-format-codes) by specifying it separated from the field name using a `>`. Eg: `%(duration>%H-%M-%S)s`, `%(upload_date>%Y-%m-%d)s`, `%(epoch-3600>%H-%M-%S)s`
 1. **Default**: A default value can be specified for when the field is empty using a `|` seperator. This overrides `--output-na-template`. Eg: `%(uploader|Unknown)s`
@@ -1417,6 +1417,7 @@ #### Redundant options
     --get-thumbnail                  --print thumbnail
     -e, --get-title                  --print title
     -g, --get-url                    --print urls
+    -j, --dump-json                  --print "%()j"
 
 
 #### Not recommended

test/test_YoutubeDL.py

@@ -668,15 +668,13 @@ def test(tmpl, expected, *, info=None, **params):
             out = ydl.escape_outtmpl(outtmpl) % tmpl_dict
             fname = ydl.prepare_filename(info or self.outtmpl_info)
 
-            if callable(expected):
-                self.assertTrue(expected(out))
-                self.assertTrue(expected(fname))
-            elif isinstance(expected, str):
-                self.assertEqual(out, expected)
-                self.assertEqual(fname, expected)
+            if not isinstance(expected, (list, tuple)):
+                expected = (expected, expected)
+            for (name, got), expect in zip((('outtmpl', out), ('filename', fname)), expected):
+                if callable(expect):
+                    self.assertTrue(expect(got), f'Wrong {name} from {tmpl}')
                 else:
-                self.assertEqual(out, expected[0])
-                self.assertEqual(fname, expected[1])
+                    self.assertEqual(got, expect, f'Wrong {name} from {tmpl}')
 
         # Side-effects
         original_infodict = dict(self.outtmpl_info)
@@ -721,7 +719,16 @@ def test(tmpl, expected, *, info=None, **params):
         # Invalid templates
         self.assertTrue(isinstance(YoutubeDL.validate_outtmpl('%(title)'), ValueError))
         test('%(invalid@tmpl|def)s', 'none', outtmpl_na_placeholder='none')
-        test('%()s', 'NA')
+        test('%(..)s', 'NA')
+
+        # Entire info_dict
+        def expect_same_infodict(out):
+            got_dict = json.loads(out)
+            for info_field, expected in self.outtmpl_info.items():
+                self.assertEqual(got_dict.get(info_field), expected, info_field)
+            return True
+
+        test('%()j', (expect_same_infodict, str))
 
         # NA placeholder
         NA_TEST_OUTTMPL = '%(uploader_date)s-%(width)d-%(x|def)s-%(id)s.%(ext)s'

yt_dlp/YoutubeDL.py

@@ -917,7 +917,7 @@ def prepare_outtmpl(self, outtmpl, info_dict, sanitize=None):
         }
         # Field is of the form key1.key2...
         # where keys (except first) can be string, int or slice
-        FIELD_RE = r'\w+(?:\.(?:\w+|{num}|{num}?(?::{num}?){{1,2}}))*'.format(num=r'(?:-?\d+)')
+        FIELD_RE = r'\w*(?:\.(?:\w+|{num}|{num}?(?::{num}?){{1,2}}))*'.format(num=r'(?:-?\d+)')
         MATH_FIELD_RE = r'''{field}|{num}'''.format(field=FIELD_RE, num=r'-?\d+(?:.\d+)?')
         MATH_OPERATORS_RE = r'(?:%s)' % '|'.join(map(re.escape, MATH_FUNCTIONS.keys()))
         INTERNAL_FORMAT_RE = re.compile(r'''(?x)
@@ -928,12 +928,15 @@ def prepare_outtmpl(self, outtmpl, info_dict, sanitize=None):
             (?:\|(?P<default>.*?))?
             $'''.format(field=FIELD_RE, math_op=MATH_OPERATORS_RE, math_field=MATH_FIELD_RE))
 
-        get_key = lambda k: traverse_obj(
-            info_dict, k.split('.'), is_user_input=True, traverse_string=True)
+        def _traverse_infodict(k):
+            k = k.split('.')
+            if k[0] == '':
+                k.pop(0)
+            return traverse_obj(info_dict, k, is_user_input=True, traverse_string=True)
 
         def get_value(mdict):
             # Object traversal
-            value = get_key(mdict['fields'])
+            value = _traverse_infodict(mdict['fields'])
             # Negative
             if mdict['negate']:
                 value = float_or_none(value)
@@ -955,7 +958,7 @@ def get_value(mdict):
                     item, multiplier = (item[1:], -1) if item[0] == '-' else (item, 1)
                     offset = float_or_none(item)
                     if offset is None:
-                        offset = float_or_none(get_key(item))
+                        offset = float_or_none(_traverse_infodict(item))
                     try:
                         value = operator(value, multiplier * offset)
                     except (TypeError, ZeroDivisionError):
@@ -2378,6 +2381,8 @@ def print_optional(field):
         elif 'url' in info_dict:
             info_dict['urls'] = info_dict['url'] + info_dict.get('play_path', '')
 
+        if self.params.get('forceprint') or self.params.get('forcejson'):
+            self.post_extract(info_dict)
         for tmpl in self.params.get('forceprint', []):
             if re.match(r'\w+$', tmpl):
                 tmpl = '%({})s'.format(tmpl)
@@ -2394,8 +2399,7 @@ def print_optional(field):
             self.to_stdout(formatSeconds(info_dict['duration']))
         print_mandatory('format')
 
-        if self.params.get('forcejson', False):
-            self.post_extract(info_dict)
+        if self.params.get('forcejson'):
             self.to_stdout(json.dumps(self.sanitize_info(info_dict)))
 
     def dl(self, name, info, subtitle=False, test=False):