def _number_finder(s, regex, numconv):
    s = regex.split(s)
    if len(s) == 1:
        return tuple(s)
    s = remove_empty(s)
    for i in range(len(s)):
        try:
            s[i] = numconv(s[i])
        except ValueError:
            pass
    if not isinstance(s[0], six.string_types):
        return [''] + s
    else:
        return s