PLUGIN_NAME = "Function $unset2(text)"
PLUGIN_AUTHOR = "Lukas Lalinsky"
PLUGIN_DESCRIPTION = "Unsets all metadata variables, except specified ones."
PLUGIN_API_VERSIONS = ["0.9.0"]

from picard.script import register_script_function

def func_unset2(parser, *args):
    for name in parser.context.keys():
        if name not in args:
            del parser.context[name]
    return u''

register_script_function(func_unset2, "unset2")