Make a new command option.
Parameters | name | regular name of the command, used in the double-dash
form and also as the parameter to the command's run()
method (unless param_name is specified). |
| help | help message displayed in command help |
| type | function called to parse the option argument, or
None (default) if this option doesn't take an argument. |
| argname | name of option argument, if any |
| short_name | short option code for use with a single -, e.g.
short_name="v" to enable parsing of -v. |
| param_name | name of the parameter which will be passed to
the command's run() method. |
| custom_callback | a callback routine to be called after normal
processing. The signature of the callback routine is
(option, name, new_value, parser). |
| hidden | If True, the option should be hidden in help and
documentation. |