Our great sponsors
-
-
WorkOS
The modern identity platform for B2B SaaS. The APIs are flexible and easy-to-use, supporting authentication, user identity, and complex enterprise features like SSO and SCIM provisioning.
-
-
-
Similarly for Typer, which is literally "the FastAPI of CLIs"[1]. Handy to type your `main` parameters and have CLI argument parsing. For more complicated cases, it's a wrapper around Click.
I'm a heavy user of type hints and enable pyright and mypy's strict modes whenever possible. However, you can't always be strict: if you use almost any package in the data science/ML ecosystem, you're unlikely to get good type inference and checking[1]. In those cases, it can still be useful to type some parameters and return values to benefit from _some_ checking, even if you don't have 100% coverage.
Type hints also bring improved completion, which is nice too.
[1] For example, huggingface's transformers library decided to drop support for full type checking because it was unsustainable but decided to keep the types for documentation[2]. There are stubs for pandas, but they're not enough because pandas has a tendency to change return types based on the input, and that breaks quickly.
https://github.com/mypyc/mypyc
> Mypyc compiles Python modules to C extensions. It uses standard Python type hints to generate fast code. Mypyc uses mypy to perform type checking and type inference.
> Mypyc can compile anything from one module to an entire codebase. The mypy project has been using mypyc to compile mypy since 2019, giving it a 4x performance boost over regular Python.
I have not experience a 4x boost, rather between 1.5x and 2x. I guess it depends on the code.
Some time ago I made a dependency injector[0] in Python using type hints. I have always enjoyed playing with type systems and I wanted to explore Python's.
I remember that it felt rough. I had issues specially with funcions using veriadic types in generics. I also remember having issues with overloading a function: sometimes it would go for the more generic one, instead of going for the more specific one when inferring types.
I managed to solve all of that. Unfortunately, that happened some time ago and I don't remember the specifics, only that it was a fun project to develop. I use it frequently in other projects.
Function annotations were added as part of Python 3.0, with PEP 3107, proposed in 2006 [0]. The first public mypy commit was in 2012 [1], and originally it was using C++-style syntax (`list lex(str s):`). The `typing` module and the official use of function annotation for type hints came in 2014 with PEP 484 [2], inspired by mypy. The first pyright commit was in 2019 (with a lot of code in the third commit [3], possibly moved from the VSCode extension).
[0] https://peps.python.org/pep-3107/
[1] https://github.com/python/mypy/commit/6f0826a9c169c4f05bb893...
[2] https://peps.python.org/pep-0484/
[3] https://github.com/microsoft/pyright/commit/1d91744b1f268fd0...
Function annotations were added as part of Python 3.0, with PEP 3107, proposed in 2006 [0]. The first public mypy commit was in 2012 [1], and originally it was using C++-style syntax (`list lex(str s):`). The `typing` module and the official use of function annotation for type hints came in 2014 with PEP 484 [2], inspired by mypy. The first pyright commit was in 2019 (with a lot of code in the third commit [3], possibly moved from the VSCode extension).
[0] https://peps.python.org/pep-3107/
[1] https://github.com/python/mypy/commit/6f0826a9c169c4f05bb893...
[2] https://peps.python.org/pep-0484/
[3] https://github.com/microsoft/pyright/commit/1d91744b1f268fd0...