def METHOD_NAME(self, key, section, dflt, is_regexp):
    # Retrieve all values from a section using a regexp
    if is_regexp:
        return [v for k, v in self.cp.items(section) if re.match(key, k)]
    value = None
    # Retrieve a single value
    try:
        value = self.cp.get(section, key)
    except configparser.NoOptionError:
        return dflt
    return value