NEW generic / alias syntax for python 3.12 (PEP 695) (intermediate) anthony explains

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  • เผยแพร่เมื่อ 24 พ.ย. 2024

ความคิดเห็น • 54

  • @MostWantedracer
    @MostWantedracer ปีที่แล้ว +38

    Here's to Anthony: The only guy who's not afraid of opening a browser window in front of you *while recording* and typing something that starts with "P".

    • @csanadtemesvari9251
      @csanadtemesvari9251 ปีที่แล้ว +3

      Incognito mode exists

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +6

      it does exist -- but this is just raw google chrome with history on

    • @calebparks8318
      @calebparks8318 ปีที่แล้ว

      For me "p" directs to "pytorch".

    • @hamzadlm6625
      @hamzadlm6625 6 หลายเดือนก่อน +1

      ​@@csanadtemesvari9251 either you don't know what incognito looks like, or you dare to assume he doesn't know that it exists, both are unrecoverably stupid

  • @rexase
    @rexase ปีที่แล้ว +7

    this is great, very Rust-like
    I think they should use for generics

    • @rosmelylawliet
      @rosmelylawliet ปีที่แล้ว +3

      i would have loved that, as `[...]` is already used for indexes/keys, whereas `` is invalid.
      i would need to check the pep to see the reason why they went this way, there's likely a reason

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +2

      my understanding is there's already usage of `[...]` in python so when generics were originally added it was "natural" with the syntax -- whereas angle brackets are only used for comparisons and would have needed a bigger lift to adopt them as a syntax construct
      maybe if they went back today and redid everything without regards for backwards compatibility it'd be with angle brackets -- but it'd be too much of a lift to just do it now

    • @PanduPoluan
      @PanduPoluan 2 หลายเดือนก่อน

      ​@@rosmelylawliet It's already used for type hinting, though, like list[int]

    • @rosmelylawliet
      @rosmelylawliet 2 หลายเดือนก่อน

      @@PanduPoluan true, i don't like that either, i think all hinting and generics should've been using
      however, i also don't mind THAT much, i'm fine as it is now, it is what it is :P

  • @unvergebeneid
    @unvergebeneid ปีที่แล้ว +19

    Well I don't know if I like this new syntax but I know I've always hated the weirdly redundant TypeVar syntax.

    • @BenjaminWheeler0510
      @BenjaminWheeler0510 ปีที่แล้ว +1

      why didn't they just use the industry standard of ? oh well

    • @Redstoner237Channel
      @Redstoner237Channel ปีที่แล้ว

      @@BenjaminWheeler0510 wasnt industry standard when python first introduced typing. Now they have to keep with it for backwards compatibility

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +7

      that's simply not true -- c# generics were 2005, java generics were 2004, c++98 had templates (and some compilers back until 1991 had some form of templates) all with angle brackets long before python typing was even an idea (mypy first released in 2009, python 3.0 syntax was 2008, the typing module was 2015)

  • @amirongoogle4795
    @amirongoogle4795 ปีที่แล้ว +11

    if it is possible, please make a video about variants; thank you.

  • @BrunoBeltran
    @BrunoBeltran ปีที่แล้ว +8

    Maybe I've been brainwashed by C++ but I find the new syntax very readable and natural.

  • @bradb4143
    @bradb4143 ปีที่แล้ว

    Looks a lot like Go generics syntax, thanks for the video!

  • @workflowinmind
    @workflowinmind ปีที่แล้ว

    5:08 That's the most logical syntax to me, what would you have preferred?

  • @mrswats
    @mrswats ปีที่แล้ว +1

    Good stuff, as per usual!

  • @hamzadlm6625
    @hamzadlm6625 6 หลายเดือนก่อน

    Thank you for sharing

  • @qexat
    @qexat ปีที่แล้ว +2

    for someone who uses typevars a lot this syntax kinda grew in me tbh…

  • @AceofSpades5757
    @AceofSpades5757 ปีที่แล้ว

    So cool! Hype 🎉

  • @yorailevi6747
    @yorailevi6747 ปีที่แล้ว

    At this point, almost all languages are functionally the same with different syntax. everything but maybe rust which can be emulated with robust linter in cpp.

  • @ismailbello513
    @ismailbello513 10 หลายเดือนก่อน

    Hi Anthony, nice video as always! would be nice to hear your thoughts on typing.Annotated!

    • @anthonywritescode
      @anthonywritescode  10 หลายเดือนก่อน +1

      tbh I haven't really used it, I steer far away from runtime annotations

  • @NicolasChanCSY
    @NicolasChanCSY ปีที่แล้ว +1

    This change does not look very intuitive...
    In addition, now the function signatures become so long when we add type hints, how should we cope with the 80-ish characters per line rule of PEP8? (Yes, I think 80-ish is still better even when we have much wider screens these days)

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +2

      it's familiar if you've worked with generics in other languages -- though they tend to use angle brackets instead

    • @probablyskela
      @probablyskela ปีที่แล้ว +1

      You can have multiline function signatures with each argument on it's own line which should eliminate the problem unless you have very, very long function, argument, and type hint names.

  • @RoyAAD
    @RoyAAD หลายเดือนก่อน

    What is the video talking about covariance ?

    • @anthonywritescode
      @anthonywritescode  หลายเดือนก่อน

      I haven't released it yet. I wasn't happy with my first two attempts at recording it and set it aside for a while

  • @iliya-malecki
    @iliya-malecki ปีที่แล้ว +2

    why is it def f[T: (str, bytes)](x:T):... and not def f[T: str | bytes](x:T):...? i tried the version that is more intuitive to me and it works. Is it not guaranteed to work? whats the deal with the whole thing?

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +2

      "it works" -- nothing is checking these in python itself -- it would be up to the typechecker to validate those
      it's a tuple because that's how it is specced -- yours is different saying that T must be a subclass of a union of int and str -- which is impossible because there exists no class which is a subclass of both int and str (so the typechecker should produce an error)

    • @iliya-malecki
      @iliya-malecki ปีที่แล้ว

      @@anthonywritescode No no when i say "it works" i mean pyright in strict mode doesnt complain. Also, "a subclass of both int and str" is an intersection type (which i know doesnt exist yet), not a union, so doesnt it mean that T is a subclass of a Union[int, str] if it is a subclass of either int or str?

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +7

      youtube deleted my response because it was too long -- I misspoke about this and got it backwards but they still mean different things (the union can be satisfied by a union whereas the tuple has distinct bounds)
      an example:
      ```
      from collections.abc import Sequence
      def f[T: int | str](a: Sequence[T], b: Sequence[T]) -> list[T]:
      return [*a, *b]
      def g[T: (int, str)](a: Sequence[T], b: Sequence[T]) -> list[T]:
      return [*a, *b]
      f([1], ['2'])
      f([1], [2])
      f(['1'], ['2'])
      # g([1], ['2']) not allowed: must be a uniform list
      g([1], [2])
      g(['1'], ['2'])
      ```

    • @iliya-malecki
      @iliya-malecki ปีที่แล้ว

      @@anthonywritescode wow, this is massive! This essentially solves the "cat in the list of animals" problem that plagues, among others, typescript. Another huge victory! Can we celebrate or should we wait for intersection types first? Also, I would love a video on intermediate/advanced typing tricks, do you plan on making one? Please do, love your content :)

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +4

      tbf this already exists but the syntax changes how it works -- you can do the same thing with TypeVar("T", int, str) vs TypeVar("T", bound=int | str)
      I do occasionally do some tricks like this but they're not always so universally applicable -- maybe I'll cover this one though

  • @BenjaminWheeler0510
    @BenjaminWheeler0510 ปีที่แล้ว +1

    I like types, yes I do. I like types, how about you?

  • @blanky_nap
    @blanky_nap ปีที่แล้ว +24

    after watching this video i have only one question: python wtf are you doing?

    • @float32
      @float32 ปีที่แล้ว +5

      I’m thinking of moving to swift. If I wanted all this complexity, I would use a compiled language and get 10x the performance, so might as well.

    • @yomajo
      @yomajo ปีที่แล้ว

      For most of my usecases I use built in types or my own classes for typehints, and have no idea what a Generic is... This seems like a woke trend in python. A shame.

    • @lonterel4704
      @lonterel4704 ปีที่แล้ว

      ​@@float32but swift is not good outside of macos. What do you use Python for?

  • @fuadnafiz98
    @fuadnafiz98 ปีที่แล้ว +1

    How do you remember all the syntaxs without any code completion or autosuggesions? 🙄

    • @timbrap4693
      @timbrap4693 ปีที่แล้ว +4

      Some people are just built different

    • @juniorceccon
      @juniorceccon ปีที่แล้ว +6

      That kind of skill is built over time. Eventually, you get used to it.

    • @IonizedComa
      @IonizedComa ปีที่แล้ว

      its easier to do it with python because it's an easily read language, i'm able to do it with C as well. But Java and C++ I have problems remembering most things. Also depends on which language you use often

  • @calebparks8318
    @calebparks8318 ปีที่แล้ว

    Hurray! Good riddance to "from ___future___ import annotations."

  • @ericng8807
    @ericng8807 ปีที่แล้ว

    3:00 AI grifters fuming right now

  • @MrYevelnad
    @MrYevelnad ปีที่แล้ว

    IDK why python implemented generics when its a dynamically typed language. I'm kinda hyped when I first knew this and it is much simpler to implement in 3.12. I play with it a bit and came to a conclusion that it is pretty much useless in python.

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +1

      it's not for the runtime, it's for type checkers

  • @mailoisback
    @mailoisback ปีที่แล้ว +2

    No performance gain, just useless syntax stuff that is littering Python.

    • @anthonywritescode
      @anthonywritescode  ปีที่แล้ว +3

      technically this performs better than TypeVar(...) calls since it's all lazily evaluated -- and 3.12 did improve performance quite a bit for basically everything
      not defending the syntax in any way -- just correcting your baseless complaints

    • @user-qi5kb5th7y
      @user-qi5kb5th7y 6 หลายเดือนก่อน +1

      yada yada, try supporting a project without type hints, where everything is a plain dict
      then we'll talk about 'littering'