lexer.py 文件源码

def expect(self, expr):
        """Expect a given token type and return it.  This accepts the same
        argument as :meth:`jinja2.lexer.Token.test`.
        """
        if not self.current.test(expr):
            expr = describe_token_expr(expr)
            if self.current.type is TOKEN_EOF:
                raise TemplateSyntaxError('unexpected end of template, '
                                          'expected %r.' % expr,
                                          self.current.lineno,
                                          self.name, self.filename)
            raise TemplateSyntaxError("expected token %r, got %r" %
                                      (expr, describe_token(self.current)),
                                      self.current.lineno,
                                      self.name, self.filename)
        try:
            return self.current
        finally:
            next(self)