Expert Python Programming - Third Edition

Argument checking

Checking the arguments that a function receives or returns can be useful when it is executed in a specific context. For example, if a function is to be called through XML-RPC, Python will not be able to directly provide its full signature like it does in statically-typed languages. This feature is needed to provide introspection capabilities when the XML-RPC client asks for the function signatures.

The XML-RPC protocolThe XML-RPC protocol is a lightweight Remote Procedure Call protocol that uses XML over HTTP to encode its calls. It is often used instead of SOAP for simple client-server exchanges. Unlike SOAP, which provides a page that lists all callable functions (WSDL), XML-RPC does not have a directory of available functions. ...