def filter_mask(data_dic, SYMBOL_LIST, TOLERANT, MASK): new_dic = {} for key in data_dic.keys(): seq = data_dic[key][4] os.environ["seq"] = seq mask = Pick70_mask.mask(seq, SYMBOL_LIST, TOLERANT) if mask <= MASK: new_dic[key] = data_dic[key][:] print "mask:", len(data_dic.keys()), len(new_dic.keys()) return new_dic