gistfile1.txt

def generate_fen(board :list=list(), turn :str='W'):

    def format_rank(rank :list):
 
        return map(lambda x: x[1].__getattribute__({"B":"lower", "W":"upper"}[x[0]])() if str(x).isalpha() else None, rank)

    def collate_rank(rank :list):
     
        string = [[k, list(g)] for k,g in groupby(format_rank(rank[1:]))]
        return str().join(map(lambda x: str(len(x[1])) if not x[0] else str().join(x[1]), string))

    return "{}\{}".format('\\'.join(list(map(collate_rank, board[1:]))), turn)

def decode_fen(fenStr :str=""):

    def unpack_rank(rank :str):

        def format(x):
            return " "*int(x.group())
        return map(lambda x: x*2 if not x.isalpha() else x, re.sub(re.compile('\d'), format , rank))

    def format_rank(rank :str):

        return list(map(lambda x: "{}{}".format("b" if x.islower() else 'W', x).upper() if x.isalpha() else x, rank))

    def fix_list(array :list):

        return [ ["  " for i in range(BOARDDIMENSION+1)], *list(map(lambda x: ["  "] + x, array))]


    validate = re.compile(r"([\w\d]+\\)+[WB]")

    if not re.match(validate, fenStr):
        return None, None
        # verify that the fen string is complete

    chain_funcs = lambda x: format_rank(unpack_rank(x))
    fen_list = fenStr.split("\\")
    return fix_list(map(chain_funcs, fen_list[:-1])), fen_list[-1]