In a framework such as Django, I’d imagine that if a user lands on a page (running a view function called “some_page”), and you have 8 imports at the top of module that are irrelevant to that view, you’re wasting cycles on those imports. My questions are:
- Is it a large enough amount of resources to make an impact on a high-traffic website?
- Is it such a bad practice to import inside of a function for this purpose that it should be avoided at said impact?
Note: This could be considered premature optimization, but I’m not interested in that argument. Let’s assume, for the sake of practical theory, that this is a completed site with loads of traffic, needing to be optimized in every way possible, and the application code, as well as DB have been fully optimized by 50 PhD database admins and developers, and these imports are the only thing left.
No, don’t do this. In a normal python execution environment on the web (mod_wsgi, gunicorn, etc.) when your process starts those imports will be executed, and then all subsequent requests will not re-execute the script. If you put the imports inside the functions they’ll have to be processed every time the function is called.