require a long-lived connection to each user. Tornado can be roughly divided into three major components: • A web framework (including RequestHandler which is subclassed to create web applications, and library including the classes IOLoop and IOStream, which serve as the building blocks for the HTTP components and can also be used to implement other protocols. The Tornado web framework and HTTP server together in Tornado generally return placeholder objects (Futures), with the exception of some low- level components like the IOLoop that use callbacks. Futures are usually transformed into their result with the

Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Web framework tornado.web — RequestHandler and Error Handling Redirection Asynchronous handlers Templates and UI Configuring templates Template syntax Security Internationalization UI modules Authentication and security Cookies and signed cookies require a long-lived connection to each user. Tornado can be roughly divided into three major components: A web framework (including RequestHandler which is subclassed to create web applications, and

just be a parenthesized value. () represents the empty (length-0) tuple. 9.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries

just be a parenthesized value. () represents the empty (length-0) tuple. 9.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries

just be a parenthesized value. () represents the empty (length-0) tuple. 9.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries

just be a parenthesized value. () represents the empty (length-0) tuple. 8.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries

just be a parenthesized value. () represents the empty (length-0) tuple. 8.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries

just be a parenthesized value. () represents the empty (length-0) tuple. 9.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries

just be a parenthesized value. () represents the empty (length-0) tuple. 9.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries

just be a parenthesized value. () represents the empty (length-0) tuple. 9.8 Named Tuples The components of tuples can optionally be named, in which case a named tuple is constructed: julia> x = (a=2 code loading mechanism allows the same package name to refer to different packages in different components of an application. Julia supports federated package management, which means that multiple independent to your project. The mechanism for combining the roots, graph and paths data structures of the components of an environ- ment stack is simple: they are merged as dictionaries, favoring earlier entries