def send_error(self, code, message=None):

        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)
        # using _quote_html to prevent Cross Site Scripting attacks (see bug #1100201)
        content = (self.error_message_format %
                   {'code': code, 'message': _quote_html(message), 'explain': explain})
        self.send_response(code, message)
        self.send_header("Content-Type", self.error_content_type)
        self.send_header('Connection', 'close')
        self.end_headers()
        if self.command != 'HEAD' and code >= 200 and code not in (204, 304):
            self.wfile.write(content)
Send and log an error reply.
dataset/ETHPy150Open kleientertainment/ds_mod_tools/pkg/win32/Python27/Lib/BaseHTTPServer.py/BaseHTTPRequestHandler.send_error