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Python developers are embracing type hints

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Re: Python developers are embracing type hints

#31

Post by letmeinhere »

mrln wrote: post #11
Waterluvian wrote: post #10

Typescript turned me into a believer but my gosh do python typings feel clumsy and quickly busy up files. I get why, and it’s not exactly realistic, but I wish a lot of it didn’t require an import. Whatever the solution is, it doesn’t include giving up on Python typings.

With the newest Python versions, most of the time I don't need typing imports!

Yeah post 3.10 you don't need Union, Optional, List, Duct, Tuple. Any still necessary when you want to be permissive, and I'm still hoping for an Unknown someday...

Re: Python developers are embracing type hints

#32

Post by smilliken »

simonw wrote: post #25

The thing that finally got me on board with optional type hints in Python was realizing that they're mainly valuable as documentation. But it's really valuable documentation! Knowing what types are expected and returned just by looking at a function signature is super useful.

The best kind of documentation is the kind you can trust is accurate. Type defs wouldn't be close to as useful if you didn't really trust them. Similarly, doctests are some of the most useful documentation because you can be sure they are accurate.

Re: Python developers are embracing type hints

#33

Post by mjr00 »

lysace wrote: post #30
simonw wrote: post #25

The thing that finally got me on board with optional type hints in Python was realizing that they're mainly valuable as documentation. But it's really valuable documentation! Knowing what types are expected and returned just by looking at a function signature is super useful.

Decent argument in principle. It still sucks for non-obvious types though: https://old.reddit.com/r/Python/comments/10zdidm/why_type_hi... Edit: Yes, one can sometimes go with Any, depending on the linter setup, but that's missing the point, isn't it?

As the top comment says, if you don't know or want to define the type just use Any. That's what it's there for.

That entire Reddit post is a clueless expert beginner rant about something they don't really understand, unfortunate that it's survived as long as it has or that anyone is taking it as any sort of authoritative argument just because it's long.

Re: Python developers are embracing type hints

#34

Post by imron »

circadian wrote: post #19

I really love Python for it's expedience, but type hints still feel like they don't belong in the language. They don't seem to come with the benefits of optimisation that you get with static typed languages. As someone who uses C and Julia (and wishes they had time for Rust), introducing solid typing yields better end results at a minimum, or is a requirement at the other end of the scale. The extra typing clarificat…

> I don't use advanced features of IDEs

I use vanilla vim (no plugins) for my editor, and still consider type hints essential.

Re: Python developers are embracing type hints

#35

Post by tecoholic »

I love typing in Python. I learnt programming with C++ and OOPs. It was freeing when I took up Python to note care about types, but I have come to enjoy types as I got older.

But, boy have we gone overboard with this now? The modern libraries seem to be creating types for the sake of them. I am drowning in nested types that seem to never reach native types. The pain is code examples of the libraries don’t even show them.

Like copy paste an OpenAI example and see if LSP is happy for example. Now I have gotten in this situation where I am mentally avoiding type errors of some libraries and edging into wishing Pydantic et al never happened.

Re: Python developers are embracing type hints

#36

Post by pdonis »

mjr00 wrote: post #33
lysace wrote: post #30

Earlier quoted context omitted.

Decent argument in principle. It still sucks for non-obvious types though: https://old.reddit.com/r/Python/comments/10zdidm/why_type_hi... Edit: Yes, one can sometimes go with Any, depending on the linter setup, but that's missing the point, isn't it?

As the top comment says, if you don't know or want to define the type just use Any. That's what it's there for. That entire Reddit post is a clueless expert beginner rant about something they don't really understand, unfortunate that it's survived as long as it has or that anyone is taking it as any sort of authoritative argument just because it's long.

> if you don't know or want to define the type

That's not the issue the reddit post is raising. The reddit post is pointing out that what a "type" is is not as simple as it looks. Particularly in a language like Python where user-defined types proliferate, and can add dunder methods that affect statements that involve built-in operations. "Just use Any" doesn't solve any of those problems.

> just use Any.

All the above said: not putting a type in at all is even easier than using Any, and is semantically equivalent.

Re: Python developers are embracing type hints

#37

Post by ehutch79 »

Spivak wrote: post #28
scuff3d wrote: post #22

Earlier quoted context omitted.

It's not even close compared to working with Java or Go or any language built with static typing in mind. To be clear, I'm not opposed to type hints. I use them everywhere, especially in function signatures. But the primary advantage to Python is speed (or at least perceived speed but that's a separate conversation). It is so popular specifically because you don't have to worry about type checking and can just move.…

But TypeScript erases (its) types at runtime, exactly like Python. Python is Python's TypeScript. Whether you want TS or JS-like semantics is entirely dependent on whether you use a type checker and whether you consider its errors a build breaker.

Not it doesn’t. It doesn’t throw errors, but they’re still introspectable in python, unlike typescript

Re: Python developers are embracing type hints

#38

Post by budro »

scuff3d wrote: post #8
imron wrote: post #6

I enforce strong types on all Python code I’m responsible for - and make sure others don’t play fast and loose with dict[str, Any] when they could use a well defined type. Doing otherwise is just asking for prod incidents.

I worked on a project that did this. Drove me absolutely nuts. It's like having all the worst parts of a dynamic language and a static language with none of the benefits. I'd much rather just work in a statically typed language from the start.

Type hints seem fantastic for when you're in maintenance mode and want to add sanity back to a system via automated tooling.

However for new projects I find that I'd much rather pick technologies that start me off with a sanity floor which is higher than Python's sanity ceiling. At this point I don't want to touch a dynamically typed language ever again.

Re: Python developers are embracing type hints

#39

Post by biimugan »

In addition to what others have mentioned, it also just makes it easier to come back later to a code base and make changes, especially refactoring. In many cases you don't even really have to add many type hints to get benefits from it, since many popular libraries are more-or-less already well-typed. It can also substitute for many kinds of unit tests that you would end up writing even 5 years ago. If you're an infrastructure engineer or data scientist that's usually just writing a lot of glue code, then it greatly helps speed up your output (I've found)

Re: Python developers are embracing type hints

#40

Post by fnord77 »

scuff3d wrote: post #23

Or you could just use a statically typed language and get a much better experience.

A entire class of bugs, wiped out by a thing called a "compiler". Gigahours of downtime and bug fixing globally prevented by a modest extra step up front. Great stuff.
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