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A comment on Open-sourcing MonkeyType – Let your Python code type-hint itself. Parent comment

Re:Open-sourcing MonkeyType – Let your Python code type-hint... by imiric on Thursday December 21, 2017 @05:54PM (#15983631)
To add to this, note that type hinting is quite a new feature in Python (introduced in v3.5, released in 2015), and this functionality simply wasn't available before. So any company heavily invested in Python today obviously wants to improve their runtime reliability, without having to rewrite parts of their stack.

Stricter typing goes a long way to achieve this, and gradual typing allows you to upgrade the code base at your own pace, which is great.

Consider this study[0] about TypeScript and Flow, which use the same approach for JavaScript, which found both able to detect ~15% of runtime bugs. So no wonder companies with large Python code bases would be the first to invest in this space.

Personally I feel this is a great addition to the language, and hope type checking becomes a first class citizen too, instead of being delegated to external tools like mypy[1] or pytype[2].

[0]: http://ttendency.cs.ucl.ac.uk/projects/type_study/

[1]: http://mypy-lang.org/

[2]: https://github.com/google/pytype

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Re:Open-sourcing MonkeyType – Let your Python code type-hint... by miohtama on Thursday December 21, 2017 @06:45PM (#15983966)
Dropbox is very heavily invested in Python. I am under impression they hired Guido van Rossum to do exactly this, among other things. First 100% statically type the old codebase, then port it to Python 3.

You can statically type Python 2 codebases, but the language does not offer native support for it. Thus, all needs to go to docstrings or comments.

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Re:Open-sourcing MonkeyType – Let your Python code type-hint... by jw- on Thursday December 21, 2017 @07:11PM (#15984104)
I'd consider those languages optionally typed, rather than gradually typed, as they don't insert run-time type checks. Regardless, I still think it's all interesting and valuable work.
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