Python type hints may not be not for me in practice

Post by pmontra » Thu, Nov 28, 2024, 8:09 AM UTC

josephg wrote: post #145

zmgsabst wrote: post #136

Earlier quoted context omitted.

I have the opposite experience: Inserting a library that wraps an existing one to add new features has been a nightmare in every statically typed language I’ve used — including times it’s virtually impossible because you’d need the underlying library to understand the wrapper type in its methods. In Python (with duck typing), that’s a complete non-issue.

Can you give an example? I think part of the problem is that mixins and such are so hard to do in most statically typed languages that programmers just don’t code things that way. I see your point - I certainly find myself reaching for clever high level patterns less in typescript than I do in JavaScript because complex typing can get in the way. But also, programs that make heavy use of metaprogramming are often, al…

Post by josephg » Thu, Nov 28, 2024, 9:30 AM UTC

pmontra wrote: post #172

josephg wrote: post #145

Earlier quoted context omitted.

Can you give an example? I think part of the problem is that mixins and such are so hard to do in most statically typed languages that programmers just don’t code things that way. I see your point - I certainly find myself reaching for clever high level patterns less in typescript than I do in JavaScript because complex typing can get in the way. But also, programs that make heavy use of metaprogramming are often, al…

I'm not the person you asked the question to but I had an unpleasant experience with Typescript recently. I used a HTTP requests library in a nuxtjs app (probably nuxt's native library) and I spent too much of my time conjuring the request and response types that would please the type checker. It was extremely frustrating because the code would work in Javascript but the compiler wouldn't accept it because of typing.…

    fetch('foo.json', {...} as any)

Post by maleldil » Thu, Nov 28, 2024, 10:47 AM UTC

Hackbraten wrote: post #160

maleldil wrote: post #85

Earlier quoted context omitted.

The old stuff never stopped working, though. You can still use Optional, Union, TypeAlias, and import collection protocols from typing. You don't have to migrate if you don't want to. They're not even deprecated.

I encourage you to open the `typing` documentation [0] and search for the word `deprecated`. Spoiler alert: the search result will be three-figure. Some of the results are already scheduled for removal. [0]: https://docs.python.org/3/library/typing.html

Post by pmontra » Thu, Nov 28, 2024, 10:51 AM UTC

josephg wrote: post #174

pmontra wrote: post #172

Earlier quoted context omitted.

I'm not the person you asked the question to but I had an unpleasant experience with Typescript recently. I used a HTTP requests library in a nuxtjs app (probably nuxt's native library) and I spent too much of my time conjuring the request and response types that would please the type checker. It was extremely frustrating because the code would work in Javascript but the compiler wouldn't accept it because of typing.…

Sounds like a bug in the type definitions. Thats an unfortunate consequence of typescript being glued to javascript: If you import a package that is authored in javascript, there's no guarantee that the type definitions are written correctly or kept up to date. Sometimes they don't exist at all. It doesn't happen too often, but its definitely annoying. In cases like this, the easiest way is to just add as any to your…

  const response = await fetch(
    url,
    {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(reqData),
    }
  );
  const resData: ApiResponse = await response.json();

Post by maleldil » Thu, Nov 28, 2024, 11:00 AM UTC

josephg wrote: post #144

liontwist wrote: post #95

Earlier quoted context omitted.

No it hasn’t? C++ type system has hardly changed (until concepts) and is one of the most powerful available. A certain generation of devs thought types were academic nonsense and then relearned the existence of those features in other languages. Now they are zealots about using them.

I think the point is that in newer languages like typescript, the price paid for static typing is lower because type inference does so much of the leg work. You get all the benefits of static typing, and the cost is usually tiny - you just need to define your types (a valuable exercise regardless) and add them to function signatures. We’ve come a long way from the C++ or Java I wrote when I was young, where types wer…

    #include 

    auto func(auto x, auto y) -> auto {
        return x + y;
    }

    auto main() -> int {
        auto i = func(1, 2);
        auto s = func(std::string("a"), std::string("b"));
    }