Naming within a module is very important; it is going to be visible to anyone using it and should therefore describe what it does. The same applies to function names. For example, f_to_c is fine, but the whole point of a library is that you can get what you are after without having to second-guess what the author meant. A function name such as fahrenheit_to_celcius makes much more sense.

The same applies to modules. If I were to use ra for regression analysis, it might seem like a reasonable name to use, but is it clear? The name can mean anything here. It may seem like a lot of effort to create a module called regression_analysis, but it will help other users know what to expect.