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python
mypy
Python2013–2026
python / mypy

mypy

Optional static typing for Python

81Distinct people
96Mentions
1Explicit recommenders
20.7KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Optional static typing for Python

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

PEP 695 is great. I've been using mypy every day at work in last couple years or so with very strict parameters (no any type etc) and I have experience writing real life…

gnulinux used a recommendation phrase. One indexed comment matches. This is a phrase match, not a verdict.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

Mentioned in the same Hacker News threads. That is not proof they are substitutes.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 6:01:08 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year96 dated mentions

Observed mentions: 2013-07-08 20:54:16 UTC to 2026-03-17 14:56:14 UTC.

0510152013-01-01 00:00:00 UTC to 2014-01-01 00:00:00 UTC (exclusive): 1 mentions; 1 submissions, 0 comments20132014-01-01 00:00:00 UTC to 2015-01-01 00:00:00 UTC (exclusive): 2 mentions; 2 submissions, 0 comments2015-01-01 00:00:00 UTC to 2016-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2016-01-01 00:00:00 UTC to 2017-01-01 00:00:00 UTC (exclusive): 5 mentions; 2 submissions, 3 comments2017-01-01 00:00:00 UTC to 2018-01-01 00:00:00 UTC (exclusive): 6 mentions; 0 submissions, 6 comments2018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 15 mentions; 0 submissions, 15 comments20192020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 17 mentions; 1 submissions, 16 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 10 mentions; 1 submissions, 9 comments2022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 9 mentions; 0 submissions, 9 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 11 mentions; 0 submissions, 11 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 8 mentions; 1 submissions, 7 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 7 mentions; 0 submissions, 7 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20132013-01-01 00:00:00 UTC2014-01-01 00:00:00 UTC110
20142014-01-01 00:00:00 UTC2015-01-01 00:00:00 UTC220
20152015-01-01 00:00:00 UTC2016-01-01 00:00:00 UTC101
20162016-01-01 00:00:00 UTC2017-01-01 00:00:00 UTC523
20172017-01-01 00:00:00 UTC2018-01-01 00:00:00 UTC606
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC202
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC15015
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC17116
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC1019
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC909
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC11011
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC817
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC707
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC202

What Hacker News says

10 sources
I am seeing what the GP comment says in a codebase I manage, around 47k LOC. Not massive at all, but enough where the problems mentioned above start to pop up. This is an application that runs in servers to analyze traffic data, so it has both analysis code and also a lot of code for the analysis framework. It gets hard to manage. I have unit tests and also integration tests that cover some, but not all of the code paths (it's very hard in this case to have everything covered). Most of the times, when they fail is due to something that would have been caught by static typing. The codebase is being slowly migrated to static typing. On one hand, as the parent says, the typing module is still immature and there are still some Python constructs (not too weird ones, see [1] for an example) that you can't type-check correctly. On the other hand
Read the rest
, I like the fact that you can include typing slowly and not all at once, it makes the effort much easier to tackle. And, if typing works, it works well. Regarding performance, well. Parallelism is pretty hard to do well, and the language itself is not the fastest thing. Some parts are migrated to a C extension but that's costly in terms of development and debugging time. Despite all of that, I do think that Python was the best choice for our situation, and still is. Maybe from this point onwards another language would make things easier, but without Python's library support, ease and speed of development and expressiveness the cost of just getting to market would have been far higher, and probably we wouldn't have reached this point with other languages. And migrating the codebase to another language is just not worth it at all, as there are still a lot of areas we can improve quite a lot with far less effort than a full rewrite. 1: https://github.com/python/mypy/issues/2756#issuecomment-8772...
In Faster Python with Guido van Rossum
The biggest problem with Python typing + mypy is that it's not complete: not everything can be type annotated strictly (as in, avoiding `Any`) and correctly (as in, matching actual types passing through the code and not just whatever shuts up mypy). One example is JSON-like `dict`s, since mypy doesn't support recursive types yet[1]. [1] https://github.com/python/mypy/issues/731
In I Want a New Duck (2020)

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