tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing — Unit testing support for asynchronous code tornado.util — General-purpose exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys.executable [https://docs.python.org/3

tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing — Unit testing support for asynchronous code tornado.util — General-purpose exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys.executable [https://docs.python.org/3

Documentation, Release 6.1 The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys. executable and sys.argv. Additionally parameters. • reason (str) – Keyword-only argument. The HTTP “reason” phrase to pass in the status line along with status_code. Normally determined automatically from status_code, but can be used to use

exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys. executable and sys.argv. Additionally parameters. • reason (str) – Keyword-only argument. The HTTP “reason” phrase to pass in the status line along with status_code. Normally determined automatically from status_code, but can be used to use

exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys. executable and sys.argv. Additionally parameters. • reason (str) – Keyword-only argument. The HTTP “reason” phrase to pass in the status line along with status_code. Normally determined automatically from status_code, but can be used to use

exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys. executable and sys.argv. Additionally parameters. • reason (str) – Keyword-only argument. The HTTP “reason” phrase to pass in the status line along with status_code. Normally determined automatically from status_code, but can be used to use

Automatically detect code changes in development tornado.log — Logging support tornado.options — Command-line parsing tornado.stack_context — Exception handling across asynchronous callbacks tornado.testing — exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys.executable [https://docs.python.org/3

exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys. executable and sys.argv. Additionally parameters. • reason (string) – Keyword-only argument. The HTTP “reason” phrase to pass in the status line along with status_code. Normally determined automatically from status_code, but can be used to use

exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys. executable and sys.argv. Additionally parameters. • reason (str) – Keyword-only argument. The HTTP “reason” phrase to pass in the status line along with status_code. Normally determined automatically from status_code, but can be used to use

exceptions return a 500 status. The default error page includes a stack trace in debug mode and a one-line description of the error (e.g. “500: Internal Server Error”) otherwise. To produce a custom error catch any syntax errors or other errors at startup. Reloading loses any Python interpreter command-line arguments (e.g. -u) because it re-executes Python using sys. executable and sys.argv. Additionally parameters. • reason (str) – Keyword-only argument. The HTTP “reason” phrase to pass in the status line along with status_code. Normally determined automatically from status_code, but can be used to use