Welcome to Software Development on Codidact!
Will you help us build our independent community of developers helping developers? We're small and trying to grow. We welcome questions about all aspects of software development, from design to code to QA and more. Got questions? Got answers? Got code you'd like someone to review? Please join us.
PEP20 on namespaces: What exactly is it saying to do?
PEP20 aka the Zen of Python has a statement:
Namespaces are one honking great idea -- let's do more of those!
What exactly are we supposed to "do" according to this?
Is it saying we should have more "honking great ideas" like namespaces and add them to the language as PEPs?
Is it saying we should "use namespaces more"? How do you do that?
As far as I know, Python has only one namespace system and it's not optional to use it. Everyone who writes scripts, functions, classes, methods, modules and packages is automatically subject to the rules of how Python handles namespaces. Scope in Python is intuitive so a lot of people use it without even being aware of the formal rule, because it behaves pretty much the way you expect even if you were not aware of it.
You can explicitly manipulate namespaces when you do things like eval, but this is uncommon and discouraged in normal programming.
Is there some secret technique to leveraging namespaces to become a more effective Python programmer? Or is it just a convoluted way of saying "stick with local variables/objects when you can, avoid globals"?
1 answer
To start with, it's worth noting that the Zen of Python is more about development of Python, rather than development with Python. That may mean that some bits of its wisdom are more applicable to questions about the Python language design and the interpreter that implements it than they are about anything you write in Python for your own uses.
I think we can see how the "Namespaces are one honking great idea" line makes sense in that context. It's basically an admonishment to add new features to the Python standard library, within some module's namespace, rather making things keywords or putting them into the builtin module, which would make them available all the time without any namespace prefix.
Similarly, it's reflected in language design ideas like the import statement by default adding only the imported module to the current namespace, with from some_module import * being strongly discouraged. The star import form is the default for how imports work in quite a few other languages that don't use namespaces as well or as much as Python does!
To sum up, I think you're correct that most Python programmers are going to use namespaces whether they want to or not. It's part of the Python language's design that pushes them to do that, and that design is what the Zen of Python is all about.
0 comment threads
1 comment thread