@classmethod
    def isBank(cls, s):
        if not s:
            return False
        si = s.replace('.', '')
        if not cls.isinteger(si):
            return False
        return len(si) == 9
Testing if s is a valid bank number:
dataset/ETHPy150Open petrvanblokland/Xierpa3/xierpa3/toolbox/parsers/validator.py/Validator.isBank