Python2.4 doesn't have a partition method so we provide
    our own that mimics str.partition from later releases.

    Split the string at the first occurrence of sep, and return a
    3-tuple containing the part before the separator, the separator
    itself, and the part after the separator. If the separator is not
    found, return a 3-tuple containing the string itself, followed
    by two empty strings.

def _partition(entity, sep):
    """Python2.4 doesn't have a partition method so we provide
    our own that mimics str.partition from later releases.

    Split the string at the first occurrence of sep, and return a
    3-tuple containing the part before the separator, the separator
    itself, and the part after the separator. If the separator is not
    found, return a 3-tuple containing the string itself, followed
    by two empty strings.
    """
    parts = entity.split(sep, 1)
    if len(parts) == 2:
        return parts[0], sep, parts[1]
    else:
        return entity, '', ''