def _split(f, s, a_p='', a_s='', b_p='', b_s='', reverse=False):
    """Split string on a symbol and return two string, first possible empty"""
    splitted = f.split(s)
    if len(splitted) == 1:
        a, b = '', splitted[0]
        if reverse:
            b, a = a, b
    else:
        a, b = splitted

    if a:
        a = '%s%s%s' % (a_p, a, a_s)
    if b:
        b = '%s%s%s' % (b_p, b, b_s)

    return a, b