BaseHTTPServer.py 文件源码

def send_error(self, code, message=None):
        """Send and log an error reply.

        Arguments are the error code, and a detailed message.
        The detailed message defaults to the short entry matching the
        response code.

        This sends an error response (so it must be called before any
        output has been generated), logs the error, and finally sends
        a piece of HTML explaining the error to the user.

        """

        try:
            short, long = self.responses[code]
        except KeyError:
            short, long = '???', '???'
        if message is None:
            message = short
        explain = long
        self.log_error("code %d, message %s", code, message)
        self.send_response(code, message)
        self.send_header('Connection', 'close')

        # Message body is omitted for cases described in:
        #  - RFC7230: 3.3. 1xx, 204(No Content), 304(Not Modified)
        #  - RFC7231: 6.3.6. 205(Reset Content)
        content = None
        if code >= 200 and code not in (204, 205, 304):
            # HTML encode to prevent Cross Site Scripting attacks
            # (see bug #1100201)
            content = (self.error_message_format % {
                'code': code,
                'message': _quote_html(message),
                'explain': explain
            })
            self.send_header("Content-Type", self.error_content_type)
        self.end_headers()

        if self.command != 'HEAD' and content:
            self.wfile.write(content)