[options] mark '--list-extractors' argument as optional

docs/options.md

@@ -48,13 +48,13 @@
     -K, --list-keywords         Print a list of available keywords and example
                                 values for the given URLs
     -e, --error-file FILE       Add input URLs which returned an error to FILE
-    -N, --print [EVENT:]FORMAT  Write FORMAT during EVENT (default 'prepare') to
-                                standard output. Examples: 'id' or
+    -N, --print [EVENT:]FORMAT  Write FORMAT during EVENT (default 'prepare')
+                                to standard output. Examples: 'id' or
                                 'post:{md5[:8]}'
     --print-to-file [EVENT:]FORMAT FILE
                                 Append FORMAT during EVENT to FILE
     --list-modules              Print a list of available extractor modules
-    --list-extractors CATEGORIES
+    --list-extractors [CATEGORIES]
                                 Print a list of extractor classes with
                                 description, (sub)category and example URL
     --write-log FILE            Write logging output to FILE
@@ -67,7 +67,8 @@
 
 ## Networking Options:
     -R, --retries N             Maximum number of retries for failed HTTP
-                                requests or -1 for infinite retries (default: 4)
+                                requests or -1 for infinite retries (default:
+                                4)
     --http-timeout SECONDS      Timeout for HTTP connections (default: 30.0)
     --proxy URL                 Use the specified proxy
     --source-address IP         Client-side IP address to bind to

gallery_dl/option.py

@@ -323,7 +323,7 @@ def build_parser():
     input.add_argument(
         "--no-input",
         dest="input", nargs=0, action=ConfigConstAction, const=False,
-        help=("Do not prompt for passwords/tokens"),
+        help="Do not prompt for passwords/tokens",
     )
 
     output = parser.add_argument_group("Output Options")
@@ -406,7 +406,7 @@ def build_parser():
     )
     output.add_argument(
         "--list-extractors",
-        dest="list_extractors", metavar="CATEGORIES", nargs="*",
+        dest="list_extractors", metavar="[CATEGORIES]", nargs="*",
         help=("Print a list of extractor classes "
               "with description, (sub)category and example URL"),
     )
@@ -430,12 +430,12 @@ def build_parser():
     output.add_argument(
         "--print-traffic",
         dest="print_traffic", action="store_true",
-        help=("Display sent and read HTTP traffic"),
+        help="Display sent and read HTTP traffic",
     )
     output.add_argument(
         "--no-colors",
         dest="colors", action="store_false",
-        help=("Do not emit ANSI color codes in output"),
+        help="Do not emit ANSI color codes in output",
     )
 
     networking = parser.add_argument_group("Networking Options")

gallery_dl/version.py

@@ -6,5 +6,5 @@
 # it under the terms of the GNU General Public License version 2 as
 # published by the Free Software Foundation.
 
-__version__ = "1.28.3"
+__version__ = "1.28.4-dev"
 __variant__ = None