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Python developers are embracing type hints

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Re: Python developers are embracing type hints

#141

Post by Kwpolska »

pansa2 wrote: post #127
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.

> all the popular dynamic languages have slowly become statically typed I’ve heard this before, but it’s not really true. Yes, maybe the majority of JavaScript code is now statically-typed, via Typescript. Some percentage of Python code is (I don’t know the numbers). But that’s about it. Very few people are using static typing in Ruby, Lua, Clojure, Julia, etc.

How many people are using Ruby, Lua, Clojure, Julia, etc.?

Re: Python developers are embracing type hints

#142

Post by ninetyninenine »

quietbritishjim wrote: post #104
ninetyninenine wrote: post #88

Earlier quoted context omitted.

You're actually missing the benefit of this. It's actually a feature. With python, because types are part of python itself, they can thus be programmable. You can create a function that takes in a typehint and returns a new typehint. This is legal python. For example below I create a function that dynamically returns a type that restricts a Dictionary to have a specific key and value. from typing import TypedDict def…

That's not a benefit. That's a monstrosity. And, as you heavily imply in your post, type checkers won't be able to cope with it, eliminating one if the main benefits of type hints. Neither will IDEs / language servers, eliminating the other main benefit.

>And, as you heavily imply in your post, type checkers won't be able to cope with it

I implied no such thing. literally said there's a language that already does this. Typescript. IDE's cope with it just fine.

>That's not a benefit. That's a monstrosity.

So typescript is a monstrosity? Is that why most of the world who uses JS in node or the frontend has moved to TS? Think about it.

Re: Python developers are embracing type hints

#143

Post by bushbaba »

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.

I think both found middle ground. In Java you don’t need to define the type of variables within the method. In Python people have learned types in method arguments is a good thing.

Re: Python developers are embracing type hints

#144

Post by JackSlateur »

AlienRobot wrote: post #49
tecoholic wrote: post #35

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 t…

My love for python was critically hurt when I learned about typing.TYPE_CHECKING. For those unaware, due to the dynamic nature of Python, you declare a variable type like this foo: Type This might look like Typescript, but it isn't because "Type" is actually an object. In python classes and functions are first-class objects that you can pass around and assign to variables. The obvious problem of this is that you can…

from __future__ import annotations

Re: Python developers are embracing type hints

#145

Post by _zoltan_ »

tecoholic wrote: post #35

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 t…

modern C++ is great, to be honest.

Re: Python developers are embracing type hints

#146

Post by IshKebab »

simonw wrote: post #98
ninetyninenine wrote: post #84

Earlier quoted context omitted.

This is a naive realization. When type checking is used to the maximum extent they become as just as important as unit testing. It is an actual safety contribution to the code. Many old school python developers don't realize how important typing actually is. It's not just documentation. It can actually roughly reduce dev time by 50% and increase safety by roughly 2x.

It's claims like that which used to put me off embracing type hints! I'd been programming for 20+ years and I genuinely couldn't think of any situations where I'd had a non-trivial bug that I could have avoided if I'd had a type checker - claims like "reduce dev time by 50%" didn't feel credible to me, so I stuck with my previous development habits. Those habits involved a lot of work performed interactively first -…

It depends on the project. If you're working always on one project and you have all the time in the world to learn it (or maybe you wrote it), then you can get away with dynamic types. It's still worse but possible.

But if you aren't familiar with a project then dynamic typing makes it an order of magnitude harder to navigate and understand.

I tried to contribute some features to a couple of big projects - VSCode and Gitlab. VSCode, very easy. I could follow the flow trivially, just click stuff to go to it etc. Where abstract interfaces are used it's a little more annoying but overall wasn't hard and I have contributed a few features & fixes.

Gitlab, absolutely no chance. It's full of magically generated identifiers so even grepping doesn't work. If you find a method like `foo_bar` it's literally impossible to find where it is called without being familiar with the entire codebase (or asking someone who is) and therefore knowing that there's a text file somewhere called `foo.csv` that lists `bar` and the method name is generated from that (or whatever).

In VSCode it was literally right-click->find all references.

I have yet to succeed in modifying Gitlab at all.

I did contribute some features to gitlab-runner, but again that is written in Go so it is possible.

So in some cases those claims are not an exaggeration - static types take you from "I give up" to "not too hard".

Re: Python developers are embracing type hints

#148

Post by Hamuko »

pansa2 wrote: post #127
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.

> all the popular dynamic languages have slowly become statically typed I’ve heard this before, but it’s not really true. Yes, maybe the majority of JavaScript code is now statically-typed, via Typescript. Some percentage of Python code is (I don’t know the numbers). But that’s about it. Very few people are using static typing in Ruby, Lua, Clojure, Julia, etc.

I have my doubts about majority of JavaScript being TypeScript.

Re: Python developers are embracing type hints

#149

Post by tossandthrow »

pydry wrote: post #138
adalacelove wrote: post #118

Earlier quoted context omitted.

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…

The issue with moving the ship where it's passanger wants it to be makes it more difficult for new passengers to get on.

This is clearly seen with typescript and the movement for "just use JS".

Furthermore, with LLMs, it should be easier than ever to experiment in one language and use another language for production loads.

Re: Python developers are embracing type hints

#150

Post by picafrost »

My experience adding types to un-typed Python code has convinced me that static typing should be required for anything more complicated than a single purpose script. Even in old and battle tested code bases so many tiny bugs and false assumptions are revealed and then wiped out.

It's not perfect in Python, and I see some developers introduce unnecessary patterns trying to make type-"perfect" `class Foo(Generic[T, V])` (or whatever) abstractions where they are not really necessary. But if the industry is really going all-in on Python for more than scripting, so should we for typed Python.

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