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Mypy 1.6

mypy-lang.blogspot.com

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Re: Mypy 1.6

#21

Post by networked »

baq wrote: post #2

For the past year I've worked with a large JS/TS project undergoing a slow, gradual transformation into TS - before that, for the better part of past 10 years I worked on a Python 3 + some typing, lightly enforced by mypy. I must say I don't like JS, never have, likely never won't, but Typescript is a really pleasant language, even if JS underneath is more visible than I'd like. The mix of static analysis possible wi…

Do you know about Pyright? It is a Python type checker implemented in, and apparently influenced by, TypeScript. It is from Microsoft, so the influence is not that surprising.

There was a recent HN submission about it: https://news.ycombinator.com/item?id=34222407.

I use Pyright as my primary type checker and mypy as a secondary. (For example, Pyright won't run in Termux on my phone. I could likely fix this, but mypy just installs with pipx.) There is a document comparing Pyright and mypy in the Pyright repository: https://github.com/microsoft/pyright/blob/b09f35889a9cc9b262....

Re: Mypy 1.6

#22

Post by tyingq »

I want to like type hinted python, but there's always some corner case. Which is fine if I'm writing the rules, but there are teams that force things like "no adding ignore/disable for things you can't figure out".

Re: Mypy 1.6

#23

Post by rhaps0dy »

_fdsfs12123 wrote: post #19

Has anyone had to choose between Mypy and Pyright? Which is "better"? A couple years ago I was in charge of choosing between the two, and I somewhat flippantly chose Pyright because it felt a lot faster ( Later, I realized that some popular libraries we use (django, numpy) have dedicated plugins for Mypy that you can't use with Pyright. So you have to look for Pyright-friendly type stubs or roll your own. I've genera…

Pyright is great, and IME does more inference than Mypy and flags more errors.

Mypy is catching up on speed though! Can't say I've tried any plugins.

Re: Mypy 1.6

#24

Post by bloopernova »

Somewhat offtopic, does anyone have a link to a page that describes which extensions/tools I should be using with VSCode to author Python code?

Edited to add: when you read various recommendations, they're all discrete and don't have the overall context. e.g. I installed the VSCode suggested extensions, but then read a comment that I should really be using Ruff. OK, that's good, but if I have extensions X, Y, and Z, should I add extensions A, B, and C?

Re: Mypy 1.6

#25

Post by globular-toast »

_fdsfs12123 wrote: post #19

Has anyone had to choose between Mypy and Pyright? Which is "better"? A couple years ago I was in charge of choosing between the two, and I somewhat flippantly chose Pyright because it felt a lot faster ( Later, I realized that some popular libraries we use (django, numpy) have dedicated plugins for Mypy that you can't use with Pyright. So you have to look for Pyright-friendly type stubs or roll your own. I've genera…

For Django there is django-types, a fork of django-stubs that works without the mypy plugin. There might be similar for numpy.

Re: Mypy 1.6

#26

Post by thejosh »

imjonse wrote: post #5

In the age of most projects having animated websites, videos on the homepages, ads for courses and maybe an online conference for launching a new version, I find this use of 2006-era blogspot strangely comforting.

Also has what the product actually IS in the header and everything! "Updates about mypy, an optional static type checker for Python"

Re: Mypy 1.6

#27

Post by brigadier132 »

solarkraft wrote: post #10
baq wrote: post #2

For the past year I've worked with a large JS/TS project undergoing a slow, gradual transformation into TS - before that, for the better part of past 10 years I worked on a Python 3 + some typing, lightly enforced by mypy. I must say I don't like JS, never have, likely never won't, but Typescript is a really pleasant language, even if JS underneath is more visible than I'd like. The mix of static analysis possible wi…

I find "dynamic during runtime + static during development" to be a highly potent combination because it largely prevents dumb programming mistakes and enables rich IDE hints while still allowing for enough magic to build beautiful interfaces. While they are usually a great benefit and easy enough to so, sometimes getting types just right can be more of an effort than it's worth - it's beautiful that in those cases y…

> I find "dynamic during runtime + static during development" to be a highly potent combination

Except you miss out on massive performance gains and your software runs 10x slower because of runtime type-checking. It's actually the worst of both worlds.

Re: Mypy 1.6

#28

Post by kps »

_fdsfs12123 wrote: post #19

Has anyone had to choose between Mypy and Pyright? Which is "better"? A couple years ago I was in charge of choosing between the two, and I somewhat flippantly chose Pyright because it felt a lot faster ( Later, I realized that some popular libraries we use (django, numpy) have dedicated plugins for Mypy that you can't use with Pyright. So you have to look for Pyright-friendly type stubs or roll your own. I've genera…

I don't touch Python much, so last time I wrote something, I used mypy and pyright and pylint and ruff.

Re: Mypy 1.6

#29

Post by keithasaurus »

KolmogorovComp wrote: post #14

Is anyone still using mypy, and if so why? I have replaced it by pyright [0] for a while now, and not looking back. It’s been a faster, more powerful replacement with (in my case), zero downside. [0]: https://github.com/microsoft/pyright

mypy is essentially the reference implementation. pyright probably is better as a type checker, but, for the referential aspect alone, I suspect many libraries will continue targeting mypy.

One potential benefit of mypy is that it comes with mypyc, a compiler that leverages mypy's evaluation of types. Since pyright and mypyc are not exactly equal, it makes sense to use mypy if you want to use mypyc.

Re: Mypy 1.6

#30

Post by baq »

brigadier132 wrote: post #27
solarkraft wrote: post #10

Earlier quoted context omitted.

I find "dynamic during runtime + static during development" to be a highly potent combination because it largely prevents dumb programming mistakes and enables rich IDE hints while still allowing for enough magic to build beautiful interfaces. While they are usually a great benefit and easy enough to so, sometimes getting types just right can be more of an effort than it's worth - it's beautiful that in those cases y…

> I find "dynamic during runtime + static during development" to be a highly potent combination Except you miss out on massive performance gains and your software runs 10x slower because of runtime type-checking. It's actually the worst of both worlds.

And yet machine code is basically untyped and fully dynamic. The world of computing is a strange place.
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