pyparsing.py 文件源码

def copy( self ):
        """
        Make a copy of this C{ParserElement}.  Useful for defining different parse actions
        for the same parsing pattern, using copies of the original parse element.

        Example::
            integer = Word(nums).setParseAction(lambda toks: int(toks[0]))
            integerK = integer.copy().addParseAction(lambda toks: toks[0]*1024) + Suppress("K")
            integerM = integer.copy().addParseAction(lambda toks: toks[0]*1024*1024) + Suppress("M")

            print(OneOrMore(integerK | integerM | integer).parseString("5K 100 640K 256M"))
        prints::
            [5120, 100, 655360, 268435456]
        Equivalent form of C{expr.copy()} is just C{expr()}::
            integerM = integer().addParseAction(lambda toks: toks[0]*1024*1024) + Suppress("M")
        """
        cpy = copy.copy( self )
        cpy.parseAction = self.parseAction[:]
        cpy.ignoreExprs = self.ignoreExprs[:]
        if self.copyDefaultWhiteChars:
            cpy.whiteChars = ParserElement.DEFAULT_WHITE_CHARS
        return cpy