# RESTfly API Library

With all of the work thats been done with the pyTenable library, I reached a point where I was using pyTenable’s core APISession, APIEndpoint, and APIIterator classes a lot for external work. It seemed only logical to separate these base classes from pyTenable and wrap them up into their own library to act as a framework for folks looking to build their own API libraries. The end result of this is the new Python RESTfly library, which is focused on providing a basic scaffolding to make writing API libraries similar to pyTenable’s easy and and effective.

I ended up taking a lot of the code as-is when moving it over, however I did find several areas to improve upon the basic premise as well. Some examples of these improvements are listed below:

• Refactored _check Method: The check method used for validating inputs actually works really well as-is, however I didn’t want to make assumptions on regex patterns that folks may want to use, so the new method supports overloading the built-in patterns and a new custom pattern dictionary to make extending it a bit easier.

• Refactored APIIterator: The APIIterator class leveraged a lot of private attributes for operation in pyTenable, over time I have been re-exposing those as public attributes and have been leveraging them more in various other code bits, so I just exposed them from the onset here. Further you can now use the iterator a bit more like a list in RESTfly’s variant, as you can call the index of the current page directly and even use the get method and define a default response of the index doesn’t exist.

• Standard Exceptions based on HTTP Standards: I took the HTTP standard error codes definitions and wrapped those in exceptions…almost all of them. The end result is that you’ll get an exception thrown for a 4xx or 5xx error that should match the expected type of error the API is throwing. Now I know that not all APIs play well here, and also allowed for this dictionary (which is stored in the APISession) to be overloaded if necessary. This also means that with minimal effort, you could also wrap the exceptions with some additional logic (like how the APIErrors in pyTenable will attempt to pull the Request-UUID header). This is all fairly easy to use and should all just work.

• Improved Utilities: There are several utilities that I keep needing over and over again and honestly have gotten tired of constantly re-implementing them. The dict_merge utility to merge two dictionaries together in a nice recursive way. The trunc utility to allow for truncation of a string with an included suffix (if specified) and ensure the resulting length never exceeds the length I specify. Generally basic stuff, but a chore to re-implement over and over.

• Vastly improved documentation: While I have been generally quite happy with the documentation in pyTenable, the private functions never needed the same level of detail as they were only intended to be used by the guts of the library. As I expect other folks to start using these various methods, functions, etc. I also spent some time really beefing up the doc-strings and the overall detail in the docs to bring it more in-line with my expectations for all public code.

In the end, pyTenable will eventually be refactored to use RESTfly instead of it’s own base classes, as there isn’t much of a reason to keep two independent versions of the same code. I’d expect that to be a further down the line problem however, as there is a lot more work to do with pyTenable.