I feel similar about "weight" in Python. Some people can really overdo it with the type annotations, wanting to annotate every little variable inside any procedure, even if as a human it is quite easy to infer its type and for the type checker the type is already clear. It adds so much clutter and at the end of the day I think: "Why aren't you just writing Java instead?" and that's probably where that notion originates from.

I used to be like that. When I did Java. I used to think to myself: "Oh neat! Everything has its place. interfaces, abstract classes, classes, methods, anonymous classes, ... everything fits neatly together."

That was before I learned more Python and realized: "Hey wait a moment, things that require me to write elaborate classes in Java are just a little bit of syntax in Python. For example decorators!" And slowly switched to Python.

Now it seems many Java-ers have come to Python, but without changing their mindset. Collectively they make it harder to enjoy using Python, because at workspaces they will mandate the most extreme views towards type annotations, turning Python into a Java dialect in some regards. But without the speed of Java. I have had feedback for a take-home assignment from an application process, where someone in all seriousness complained about me not using type annotations for what amounted to a single page of code(, and for using explanatory comments, when I was not given any guarantees of being able to talk with someone about the code - lol, the audacity).

Part of the problem is how people learn programming. Many people learn it at university, by using Java, and now think everything must work like Java. I mean, Java is honest about types, but it can also be annoying. Has gotten better though. But that message has not arrived yet at what I call the "Java-er mindset" when it comes to writing type annotations. In general languages or their type checkers have become quite good at inferring types.

I am not an experienced programmer, but I liked python because of the dynamic typing, but tbh no type hints are a nightmare (as I used to use python). These days I gravitate towards using type hints unless I am using an ipynb because it looks clean, but it can be a little much, it can look quite ugly. Not every usecase needs type hints is what I've learned.

A good compromise can be for example: Have your type annotations in the head of the procedure you are writing. That includes types of arguments and return type. You write it once at the head, and when you need to know you can look it up there, but you don't need to clutter the whole rest of the code. If you write well composing functions, then this will be all you ever need. If you write procedures 300 LoC, then well ... you shot yourself in the foot.

There definitely is an element of shooting oneself in ones own foot, but sometimes it seems unavoidable to me, or the effort just isn't worth it e.g. if I am using sklearn or numpy and the return types are ambiguous, then I'd have to overload each function at the head of the file or wrap it although it is clear what it does. What do you think? I think that if it's only my own code, then yes this is certainly avoidable with good composing functions.

I've come to the view that the best flow is to build a system in a dynamic language, and then - once you've got the broad strokes figured out - begin gradually typing it, where appropriate.

You definitely need to have a decent grasp of architecture to make this work - strict FP is very helpful to prevent any early spaghettification - but you ultimately get the best of both worlds this way: rapid iteration for the early stages and type safety once you develop a feel for the system you're building.

I've been doing this in Elixir in the last few months and I've really been enjoying it.

Yep, I agree with this. This is what I usually try in Python. Granted, Python is a way worse vehicle for FP than Elixir is, but I try to keep my procedures as pure functions as far as possible with not too big sacrifices in readability and performance. Most of the time a functional solution can be found, even in Python.

And maybe I am a little bit delusional thinking this, but in my experience, when you think deeply and come up with strict FP solutions, and you know what you are doing, then a lot of type issues don't arise, or are obvious to avoid. The simple fact that one thing you initialize once doesn't change over the course of its lifetime, already avoids tons of mistakes. You simply don't get this "Oh, is at that point in time that member of object x already modified, to be value y?" shit.

> Yep, I agree with this. This is what I usually try in Python. Granted, Python is a way worse vehicle for FP than Elixir is, but I try to keep my procedures as pure functions as far as possible with not too big sacrifices in readability and performance. Most of the time a functional solution can be found, even in Python.

That's really interesting. The last time I wrote any serious Python was back in the Python 2 era, so it's been a hot minute, but that Python certainly didn't feel very amenable to FP. Nice to hear that it's turned a corner. I'll keep an eye out for any use case where I could give FP-flavoured Python a spin.

> And maybe I am a little bit delusional thinking this, but in my experience, when you think deeply and come up with strict FP solutions, and you know what you are doing, then a lot of type issues don't arise, or are obvious to avoid. The simple fact that one thing you initialize once doesn't change over the course of its lifetime, already avoids tons of mistakes. You simply don't get this "Oh, is at that point in time that member of object x already modified, to be value y?" shit.

I very much agree with this, and I wish more FP evangelism focused on the many wonderful emergent properties of FP systems in production, instead of cutesy maths cleverness that turns off more people than it attracts (and those that it attracts were always going to be functional programmers to begin with).

To be clear, Python is still no good for FP, when comparing to other languages, including the aforementioned Elixir. Even though the Python ecosystem is huge, few people if any seem to spend any thought on functional data structures. And also you wouldn't be able to use them like in typical FP languages, because you don't get tail call optimization. You can only try your best in Python.

Gotchya.