class CharacterSet(object):
    def __init__(self):
        self.lowercase = 'abcdefghijklmnopqrstuvwxyz'
        self.uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
        self.numbers = '1234567890'
        self.special = "`~!@#$%^&*()_-+=[]{}\|';:/?.>," + '"'
        self.whitespace = ' \t'
    def isLetter(self, char):
        return (char in self.lowercase) or (char in self.uppercase)
    def isUppercase(self, char):
        return char in self.uppercase
    def isLowercase(self, char):
        return char in self.lowercase
    def isDigit(self, char):
        return char in self.numbers
    def isSpecialChar(self, char):
        return char in self.special
    def isWhitespace(self, char):
        return char in self.whitespace