def __init__( self, matchString, identChars=DEFAULT_KEYWORD_CHARS, caseless=False ):
        super(Keyword,self).__init__()
        self.match = matchString
        self.matchLen = len(matchString)
        try:
            self.firstMatchChar = matchString[0]
        except __HOLE__:
            warnings.warn("null string passed to Keyword; use Empty() instead",
                            SyntaxWarning, stacklevel=2)
        self.name = '"%s"' % self.match
        self.errmsg = "Expected " + self.name
        self.mayReturnEmpty = False
        self.mayIndexError = False
        self.caseless = caseless
        if caseless:
            self.caselessmatch = matchString.upper()
            identChars = identChars.upper()
        self.identChars = set(identChars)
dataset/ETHPy150Open pypa/pip/pip/_vendor/pyparsing.py/Keyword.__init__