def CreateParser(expression):
 input_string = antlr3.ANTLRStringStream(expression)
 lexer = ExpressionLexerWithErrors(input_string)
 tokens = antlr3.CommonTokenStream(lexer)
 parser = ExpressionParserWithErrors(tokens)
 return parser

def CreateParser ( expression ) : input_string = antlr3 . ANTLRStringStream ( expression ) lexer = ExpressionLexerWithErrors ( input_string ) tokens = antlr3 . CommonTokenStream ( lexer ) parser = ExpressionParserWithErrors ( tokens ) return parser
creates a expression parser .