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Python developers are embracing type hints

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Re: Python developers are embracing type hints

#131

Post by pansa2 »

jgb1984 wrote: post #117
iandanforth wrote: post #45

I hate typing in Python. I spend a good chunk of my day fighting the type checker and adding meaningless assertions, casts, and new types all to satisfy what feels like an obsessive compulsive nitpicker. "Type partially unknown" haunts my dreams. Duck typing is one of the best things about Python. It provides a developer experience second to none. Need to iterate over a collection of things? Great! Just do it! As lon…

Couldn't agree more! I've been using Python for almost 20 years, my whole career is built on it, and I never missed typing. Code with type hints is so verbose and unpythonic, making it much harder to read. Quite an annoying evolution.

As the article says, type hints represent a fundamental change in the way Python is written. Most developers seem to prefer this new approach (especially those who’d rather be writing Java, but are stuck using Python because of its libraries).

However it is indeed annoying for those of us who liked writing Python 2.x-style dynamically-typed executable pseudocode. The community is now actively opposed to writing that style of code.

I don’t know if there’s another language community that’s more accepting of Python 2.x-style code? Maybe Ruby, or Lua?

Re: Python developers are embracing type hints

#132

Post by lolive »

seanparsons wrote: post #110

As a static typing advocate I do find it funny how all the popular dynamic languages have slowly become statically typed. After decades of people saying it's not at all necessary and being so critical of statically typed languages. When I was working on a fairly large TypeScript project it became the norm for dependencies to have type definitions in a relatively short space of time.

Next stop is to agree that JSON is really NOT the semantic data exchange serialization for this "properly typed" world.

Re: Python developers are embracing type hints

#133

Post by jakobnissen »

Elucalidavah wrote: post #126
seanparsons wrote: post #110

As a static typing advocate I do find it funny how all the popular dynamic languages have slowly become statically typed. After decades of people saying it's not at all necessary and being so critical of statically typed languages. When I was working on a fairly large TypeScript project it became the norm for dependencies to have type definitions in a relatively short space of time.

> how all the popular dynamic languages have slowly become statically typed Count the amount of `Any` / `unknown` / `cast` / `var::type` in those codebases, and you'll notice that they aren't particularly statically typed. The types in dynamic languages are useful for checking validity in majority of the cases, but can easily be circumvented when the types become too complicated. It is somewhat surprising that dynami…

Julia (by default) does the latter, and its terrible. It makes it a) slow, because you have to do nonlocal inference through entire programs, b) impossible to type check generic library code where you have no actual usage, c) very hard to test that some code works generically, as opposed to just with these concrete types, and finally d) break whenever you have an Any anywhere in the code so the chain of type information is broken.

Re: Python developers are embracing type hints

#134

Post by dotancohen »

lolive wrote: post #132
seanparsons wrote: post #110

As a static typing advocate I do find it funny how all the popular dynamic languages have slowly become statically typed. After decades of people saying it's not at all necessary and being so critical of statically typed languages. When I was working on a fairly large TypeScript project it became the norm for dependencies to have type definitions in a relatively short space of time.

Next stop is to agree that JSON is really NOT the semantic data exchange serialization for this "properly typed" world.

Then what is?

Everybody knows the limitations of JSON. Don't state the obvious problem without stating a proposed solution.

Re: Python developers are embracing type hints

#135

Post by stellalo »

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…

> The extra typing clarification in python makes the code harder to read

It’s funny, because for me is quite the opposite: I find myself reading Python more easily when there are type annotations.

One caveat might be: for that to happen, I need to know that type checking is also in place, or else my brain dismissed annotations in that they could just be noise.

I guess this is why in Julia or Rust or C you have this stronger feeling that types are looking after you.

Re: Python developers are embracing type hints

#136

Post by Marazan »

My view on typing in Python (a language I have used for decades) is that if I wanted types I would use a language designed from the ground up with strong and consistent typing built-in. Not bolt on a sort of type system which actively fights against the way I use the language on a day to day basis.

I use plenty of statically typed languages, Python's type hinting does not bring me joy.

Re: Python developers are embracing type hints

#138

Post by pydry »

adalacelove wrote: post #118
seanparsons wrote: post #110

As a static typing advocate I do find it funny how all the popular dynamic languages have slowly become statically typed. After decades of people saying it's not at all necessary and being so critical of statically typed languages. When I was working on a fairly large TypeScript project it became the norm for dependencies to have type definitions in a relatively short space of time.

People adapt to the circumstances. A lot of Python uses are no longer about fast iteration on the REPL. Instead of that we are shipping Python to execute in clusters on very long running jobs or inside servers. It's not only about having to start all over after hours, it's simply that concurrent and distributed execution environments are hostile to interactive programming. Now you can't afford to wait for an exceptio…

Here we are because:

* Types are expensive and dont tend to pay off on spikey/experimental/MVP code, most of which gets thrown away.

* Types are incredibly valuable on hardened production code.

* Most good production code started out spikey, experimental or as an MVP and transitioned.

And so here we are with gradual typing because "throwing away all the code and rewriting it to be "perfect" in another language" has been known for years to be a shitty way to build products.

Im mystified that more people here dont see that the value and cost of types is NOT binary ("they're good! theyre bad!") but exists on a continuum that is contingent on the status of the app and sometimes even the individual feature.

Re: Python developers are embracing type hints

#139

Post by jakobnissen »

dandanua wrote: post #83

This is why I think Julia will win in the long run. It has an amazing type system, simple yet powerful. In particular, abstract types are much easier to define and use than abstract classes in Python.

Ooh, I completely disagree. Julia has a worse type system overall, IMO. The big downside of Julia is that Julia has no interfaces or protocols. So, you can't type assert that something is an iterable of integers, for example.

Another issue is that abstract types are completely undocumented and have no tooling support. You say it's easier to use an abstract type. Can you tell me what I need to define to create a working subtype of AbstractDict? Or Number? Or IO? It's completely undefined, and the only way to do it is to just define the type and then try it out and patch when it breaks because a method was missing.

Finally, there is no multiple inheritance. That means I can't define something which is both a subtype of AbstractArray and IO, for example.

Re: Python developers are embracing type hints

#140

Post by lolive »

flohofwoe wrote: post #130
seanparsons wrote: post #110

As a static typing advocate I do find it funny how all the popular dynamic languages have slowly become statically typed. After decades of people saying it's not at all necessary and being so critical of statically typed languages. When I was working on a fairly large TypeScript project it became the norm for dependencies to have type definitions in a relatively short space of time.

OTH I only came to realize that I actually like duck typing in some situations when I tried to add type hints to one of my Python projects (and then removed them again because the actually important types consisted almost entirely of sum types, and what's the point of static typing if anything is a variant anyway). E.g. when Python is used as a 'scripting language' instead of a 'programming language' (like for writin…

Note1: Type hints are hints for the reader. If you cleverly discovered that your function is handling any type of data, hint that!

Note2: From my experience, in Java, i have NEVER seen a function that consumes explicitely an Object. In Java, you always name things. Maybe with parametric polymorphism, to capture complex typing patterns.

Note 3: unfortunately, you cannot subclass String, to capture the semantic of its content.

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