typeguard VS PDM

As other folks have commented, type hints are now a big deal. For static typing the best checker is pyright. For runtime checking there is typeguard and beartype. These can be integrated with array libraries through jaxtyping. (Which also works for PyTorch/numpy/etc., despite the name.)

I got good use of the run-time type checking of typeguard [0] when I recently invoked it via its pytest plugin [2]. For all code visited in the test suite, you get a failing test whenever an actual type differs from an annotated type.

[0]: https://github.com/agronholm/typeguard/

[1]: https://typeguard.readthedocs.io/en/latest/userguide.html#us...

But you can use a library like typeguard to get runtime typechecking. Or run mypy over the code to get static typechecking.

Every point in this blog post strikes me as either (1) unaware of the tooling around python typing other than mypy, or (2) a criticism of static-typing-bolted-on-to-a-dynamically-typed-language, rather than Python's hints. Regarding (1), my advise to OP is to try out Pyright, Pydantic, and Typeguard. Pyright, especailly, is amazing and makes the process of working with type hints 2 or 3 times smoother IMO. And, I don't think points that fall under (2) are fair criticisms of type *hints*. They are called hints for a reason.

Otherwise, here's a point-by-point response, either recommending OP checks out tooling, or showing that the point being made is not specific to Python.

> type hints are not binding.

There are projects [0][1] that allow you to enforce type hints at runtime if you so choose.

It's worth mentioning that this is very analogous to how Typescript does it, in that type info is erased completely at runtime.

> Type checking is your job after all, ...[and that] requires maintenance.

There are LSPs like Pyright[2] (pyright specifically is the absolute best, IMO) that report type errors as you code. Again, this is very very similar to typescript.

> There is an Any type and it renders everything useless

I have never seen a static-typing tool that was bolted on to a dynamically typed language, without an `Any` type, including typescript.

> Duck type compatibility of int and float

The author admits that they cannot state why this behavior is problematic, except for saying that it's "ambiguous".

> Most projects need third-party type hints

Again, this is a criticism of all cases where static types are bolted on dynamically typed languages, not Python's implementation specifically.

> Sadly, dataclasses ignore type hints as well

Pydantic[3] is an amazing data parsing library that takes advantage of type hints, and it's interface is a superset of that of dataclasses. What's more, it underpins FastAPI[4], an amazing API-backend framework (with 44K Github stars).

> Type inference and lazy programmers

The argument of this section boils down to using `Any` as a generic argument not being an error by default. This is configurable to be an error both in Pyright[5], and mypy[6].

> Exceptions are not covered [like Java]

I can't find the interview/presentation, but Guido Van Rossum specifically calls out Java's implementation of "exception annotations" as a demonstration of why that is a bad idea, and that it would never happen in Python. I'm not saying Guido's opinion is the absolute truth, but just letting you know that this is an explicit decision, not an unwanted shortcoming.

[0] https://github.com/RussBaz/enforce

[1] https://github.com/agronholm/typeguard

[2] https://github.com/microsoft/pyright

[3] https://pydantic-docs.helpmanual.io

[4] https://github.com/tiangolo/fastapi

[5] https://github.com/microsoft/pyright/blob/main/docs/configur...

[6] https://mypy.readthedocs.io/en/stable/config_file.html#confv...

Personally I find working around mypy's quirks to be more effort than it's worth, so to offer another option: typeguard or beartype can be used to perform run-time type checking.

Never checked? They're statically checked.

Also, tooling like https://pydantic-docs.helpmanual.io/ can do runtime checking for important parts of your app or you can add use this https://github.com/agronholm/typeguard to enforce all types at runtime (although I haven't measured the performance impact, probably something to do in a separate environment than production?).

typeguard

# See https://pre-commit.com for more information # See https://pre-commit.com/hooks.html for more hooks repos: - repo: https://github.com/pre-commit/pre-commit-hooks rev: v3.2.0 hooks: - id: trailing-whitespace - id: end-of-file-fixer - id: check-yaml - id: check-toml - id: check-added-large-files - repo: local hooks: - id: tox lint name: tox-validation entry: pdm run tox -e test,lint language: system files: ^src\/.+py$|pyproject.toml|^tests\/.+py$ types_or: [python, toml] pass_filenames: false - id: tox docs name: tox-docs language: system entry: pdm run tox -e docs types_or: [python, rst, toml] files: ^src\/.+py$|pyproject.toml|^docs\/ pass_filenames: false - repo: https://github.com/pdm-project/pdm rev: 2.10.4 # a PDM release exposing the hook hooks: - id: pdm-lock-check - repo: https://github.com/jumanjihouse/pre-commit-hooks rev: 3.0.0 hooks: - id: markdownlint

PDM is a solution that allows for easy creation and management of python projects. Some of the key features that will improve the management of python projects include:

You'd need a proper dependencies management tool like PDM or Poetry to exhaustively resolve and lock down all the transitive dependencies if you want to have anything closed to reproducible build.

Are you working on a Python project that uses pdm for dependency management and dotenv for local environment variable and secrets management? Do you find it frustrating when CLI tools like pgcli don't automatically pick up your .env file, forcing you to resort to npm install -g dotenv-cli? I've got a more convenient solution for you!

I first learned about PDM from a blog post written by one of the PDM contributers. The post was about OOPifying argparse to allow for easy creation/modification of subcommands that exist as their own classes/files, and to avoid maintaining a single long script with an endless number of subparser.add_argument(...) lines.

That's more or less what PEP 582 plans to do, but it's been stalled and mired in discussions for years. The PDM tool went ahead and implemented it though if you want to use it: https://github.com/pdm-project/pdm

pdm – A modern Python package and dependency manager

pdm and PEP 582 enter the chat

I'm liking PDM for a while now. Quicker than Poetry and built according to the Python package spec in mind and not as an afterthought. While it was originally meant to work with PEP 582, it works with virtual environments too (now default).

https://github.com/pdm-project/pdm