Python’s “type hints” are a bit of a disappointment to me

Post by RhysU » Fri, Apr 22, 2022, 2:32 AM UTC

phailhaus wrote: post #67

Python's type system is a disappointment, but I don't think this article does a great job of explaining why. My biggest gripes: 1. There is no way to get typing like dataclasses without writing your own mypy plugin. The syntax is simply not expressive enough to do it. This means that if you want to be productive with a library like Pydantic, you also have to add the mypy plugin to your dependencies and add it to your…

Post by ImprobableTruth » Fri, Apr 22, 2022, 2:34 AM UTC

zmgsabst wrote: post #201

ImprobableTruth wrote: post #172

Earlier quoted context omitted.

Sure, but the idea behind gradual typing is that 'Any' should only be temporary. IMO if you're serious about it, stable code should at least pass strict type checking, if not completely forbid even explicit Any. >There’s a reason I brought up the JSON example: loading and manipulating JSON of varying structure is something I do a lot at work. Do you have a specific example that you find troublesome? For JSON with a f…

Your suggestion to “use a recursive union type” and that being “ugly … if your type checker doesn’t … support recursive types” being required to support varying JSON is my point: Python types don’t support a common Pythonism used frequently in my work. In fact, you admit that even fixed JSON can be difficult without a 3rd party library. You’re lecturing me like I don’t understand types without realizing that you repe…

  JSON = Union[
      None,
      bool, 
      int,
      float,
      str,
      List['JSON'],
      Dict[str, 'JSON'],
  ]

Post by remram » Fri, Apr 22, 2022, 2:37 AM UTC

Humphrey wrote: post #118

While I love the idea behind Python's type hints, they are merely a shadow of the success of TypeScript. Like the author, I've mostly given up on adding type hints in my Python code. I now only use them when I want to help my IDE find autocomplete suggestions. Whereas TypeScript was a game changer for JavaScript. I used to hate JavaScript, but somehow TypeScript has become one of my favourite languages! How has the a…

Post by goodoldneon » Fri, Apr 22, 2022, 2:44 AM UTC

Frotag wrote: post #132

Humphrey wrote: post #118

While I love the idea behind Python's type hints, they are merely a shadow of the success of TypeScript. Like the author, I've mostly given up on adding type hints in my Python code. I now only use them when I want to help my IDE find autocomplete suggestions. Whereas TypeScript was a game changer for JavaScript. I used to hate JavaScript, but somehow TypeScript has become one of my favourite languages! How has the a…

This is exactly my experience. I've also found that Python's type annotations for even basic stuff like are way clunkier to write. For example an optional requires a typing.Optional import or a an ugly "| None" instead of a question mark like TS has. And good luck trying to annotate some complex / nested json, you'll need a bazillion intermediary classes.

  function foo1(value?: number) {}
  
  foo1()

  function foo2(value: number | undefined) {}
  
  foo2()

Post by goatlover » Fri, Apr 22, 2022, 2:48 AM UTC

minism wrote: post #256

tootie wrote: post #254

Earlier quoted context omitted.

I'm baffled by people loving type hints in python when strongly typed languages have been widely available for so long. This is why people liked java and c#.

Same thing happened to the JS world with typescript (though typescript seems more powerful than python type annotations). Its fine though - I'm glad the culture is trending towards understanding that strong typing saves you time rather than causes you extra time. This is true even for very small and simple programs, and even if you're the only developer.