Why do we need to document our code and how to start with Continuous Documentation?

Can we deploy yet?: Continuous Integration. This is one of the parts in series "How to make your Python code ready for production"

Can we deploy yet?: Logging. This is one of the parts in series "How to make your Python code ready for production"

Can we deploy yet?: Exceptions. This is one of the parts in series "How to make your Python code ready for production"

How to make sure that our beloved Python code is ready for production? How can we make our backend ready for upcoming troubles with real customers using our application?