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
