Move `--dice-sides` option to main.

diceware/__init__.py

@@ -116,6 +116,13 @@ def handle_options(args):
             "Use words from this wordlist. Possible values: `%s'. "
             "Wordlists are stored in the folder displayed below. "
             "Default: en_securedrop" % "', `".join(wordlist_names)))
+    realdice_group = parser.add_argument_group(
+        "Arguments related to `realdice' randomsource",
+        )
+    realdice_group.add_argument(
+            '--dice-sides', default=6, type=int, metavar="N",
+            help='Number of sides of dice. Default: 6'
+        )
     parser.add_argument(
         'infile', nargs='?', metavar='INFILE', default=None,
         type=argparse.FileType('r'),

tests/exp_help_output.txt

 usage: diceware [-h] [-n NUM] [-c | --no-caps] [-s NUM] [-d DELIMITER]
-                [-r SOURCE] [-w NAME] [-v] [--version] [--dice-sides N]
+                [-r SOURCE] [-w NAME] [--dice-sides N] [-v] [--version]
                 [INFILE]
 
 Create a passphrase
@@ -25,7 +25,8 @@ optional arguments:
                         the folder displayed below. Default: en_securedrop
   -v, --verbose         Be verbose. Use several times for increased verbosity.
   --version             output version information and exit.
-  --dice-sides N        Number of sides of dice when using ``realdice`` as
-                        `randomsource`. Default: 6
+
+Arguments related to `realdice' randomsource:
+  --dice-sides N        Number of sides of dice. Default: 6
 
 Wordlists are stored in <WORDLISTS-DIR>