b.o.ListOption(Option) : class documentation

Part of bzrlib.option View In Hierarchy

Option used to provide a list of values.

On the command line, arguments are specified by a repeated use of the
option. '-' is a special argument that resets the list. For example,
  --foo=a --foo=b
sets the value of the 'foo' option to ['a', 'b'], and
  --foo=a --foo=b --foo=- --foo=c
sets the value of the 'foo' option to ['c'].