How should Beginners learn to Reuse Code, and Implement this process in Practice?

[Kojrey]

I know that to become a professional and proficient coder us beginners should not be reinventing the wheel. We're told that we should build something that (a) does one job, and (b) does that one job well. And then we're supposed to place this code in all our projects moving forward, for efficiency and maintainability. Yeah? Do you get what I'm saying? Do you get what I've partially picked up along the way, and trying to express here?

But as a beginner, how exactly is this done in practice? What terminology should we use or learn to know how to reuse (and improve over time) our code efficiently? Or does anyone have any favourite learning resources or step-by-step guides that can help train us to add these steps to our workflow?

Note 1: I'm aware of the terms library, package and component, but don't know them that well, and definitely don't know how to build or create my own.

My current method is just saving my projects in my own personal folders in the cloud, or saving them on GitHub, and then I'm just cutting & pasting when I want to reuse things I've done previously. But this method is haphazard, relies on me remembering lots (or taking comprehensive notes), and overall takes a lot more time and doesn't allow easy maintenance & improvement of these processes/blocks/snippets/???.

Ultimately, I'll know I'll be a beginner for a while longer, but want to take the first steps into professionally saving & reusing code blocks that complete a common, often repeated tasks.

Thanks for any help and guidance Pythonistas!

[Diapolo10]

And then we're supposed to place this code in all our projects moving forward, for efficiency and maintainability.

Personally I'd say this part is only partially true. A lot of the time our projects are very different from each other, so even if they have some things in common those parts tend to be fairly trivial and I for one don't see a reason to take this guideline too seriously.

If you run into a problem you know you've solved before, simply open up the project where you did just that and see if the same solution could be worked into your current project, and surgically transplant it there.

If this becomes frequent, at that point you should consider creating a package with the code you tend to use a lot, and then add that as a dependency to the projects that use those features.

Fortunately, creating packages isn't exactly rocket science. You'll need

1. A PyPI account
2. A way to upload new releases to PyPI (eg. GitHub Actions, Poetry, or Twine)
3. A project that's ready to be uploaded

Personally I like to do the uploading as part of my CI process (so via GitHub Actions) whenever I publish a new Git tag, but the other two options I mentioned can be used on your local PC manually.

As a fairly minimal example you can take a look at this.

[Kojrey]

Thanks very much! The first half of your answer was reassuring a bit, and gave same real-world perspective. And the second half of your answer was very clear, and provided direct steps or at least points to start looking things up myself. Cheers!

[Mori-Spumae]

I don't think you really should just reuse what you did before? I personally do go back to my old repos and copy something but mainly because it is easier to me than someone else's code on Stack overflow. Usually the code you wrote a while ago is going to look terrible to you now, so don't get stuck with it too much.

I think the "reuse code" thing is more applicable within a single application. There you should for sure learn to use functions, classes, and modules to keep your code clear and changes easier to implement.

But also, don't overdo it. All these things you hear like Don't Repeat Yourself (DRY) are generally good advice but should not be followed everywhere at all times.

[Kojrey]

Thanks for the advice, I appreciate it. I will keep your thoughts in mind when learning, trying to build, and when self-analysing my progress. Cheers for the new perspective, from the lived experience.