Mypy Blog

Django has quite a lot of "magic" as well. There is work being done on a mypy plugin to support this magic in addition to type stubs. It is already quite usable and supports type-checking many common patterns: https://github.com/mkurnikov/django-stubs See also mypy's recent blog post on plugins (which are also used for supporting Python 3.7's dataclasses, which are quite dynamic as well): http://mypy-lang.blogspot.com/2019/03/extending-mypy-with-plugins.html

This sounds similar to Dropbox's PyAnnotate -- Guido van Rossum writes about it here: http://mypy-lang.blogspot.co.uk/2017/11/dropbox-releases-pyannotate-au… Would be interesting to see how MonkeyType and PyAnnotate compare.

I wonder how this compares to PyAnnotate: http://mypy-lang.blogspot.ca/2017/11/dropbox-releases-pyannotate-auto.…

It's cool that PyCharm added support for this -- the point of the typing module and the type hinting PEP is for IDEs to adopt it for linting purposes. For those of you using vim, emacs, and the standard UNIX editing toolchain, the mypy linter provides command-line support. This blog post from April 2015 describes the first version of mypy that includes support for the official typing library. http://mypy-lang.blogspot.co.uk/2015/04/mypy-02-released.html

> 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 mypy config. Otherwise, no typing. This would be solved by PEP 681, which originates from (and is already used in) pyright: https://peps.python.org/pep-0681/ > 3. To this day, there is still no way to express optional keys. Not "Optional" keys, but keys that can be left out of your dictionary. The closest you can get is this weird hack where you can set `total=False` in your TypedDict, which makes all keys optional. This is solved by PEP 655, which introduces NotRequired: https://peps.python.org/pep-0655/ It's implemented in mypy 0.930: https://mypy-lang.blogspot.com/2021/12/mypy-0930-released.html > I really wish Python learned from Typescript, but it's too late at this point Personally, I feel like it's partly just entirely different styles: Python relies on a mix of nominal and duck types, whereas JavaScript is much more focused on structural typing. As a result, there are a lot of things like TypedDict that are absolutely essential for JS to even function but a decent bit less so in idiomatic Python code (keeping a significant amount of dicts around uses much more memory than objects, I recall a PyCon talk explicitly mentioning this too).