Flake8 VS mypy

Compare Flake8 vs mypy and see what are their differences.


flake8 is a python tool that glues together pycodestyle, pyflakes, mccabe, and third-party plugins to check the style and quality of some python code. (by PyCQA)
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Flake8 mypy
31 106
3,102 16,822
3.1% 1.9%
8.0 9.7
3 days ago about 16 hours ago
Python Python
GNU General Public License v3.0 or later GNU General Public License v3.0 or later
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.


Posts with mentions or reviews of Flake8. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2023-10-05.


Posts with mentions or reviews of mypy. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2023-11-19.
  • It's Time for a Change: Datetime.utcnow() Is Now Deprecated
    5 projects | news.ycombinator.com | 19 Nov 2023
    It's funny you should say this.

    Reading this article prompted me to future-proof a program I maintain for fun that deals with time; it had one use of utcnow, which I fixed.

    And then I tripped over a runtime type problem in an unrelated area of the code, despite the code being green under "mypy --strict". (and "100% coverage" from tests, except this particular exception only occured in a "# pragma: no-cover" codepath so it wasn't actually covered)

    It turns out that because of some core decisions about how datetime objects work, `datetime.date.today() < datetime.datetime.now()` type-checks but gives a TypeError at runtime. Oops. (cause discussed at length in https://github.com/python/mypy/issues/9015 but without action for 3 years)

    One solution is apparently to use `datetype` for type annotations (while continuing to use `datetime` objects at runtime): https://github.com/glyph/DateType

  • What's New in Python 3.12
    5 projects | news.ycombinator.com | 18 Oct 2023
    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 programs with Rust, Agda, and some Haskell before, so I'm familiar with strict type systems. I'm sure many will disagree with me but these are my very honest opinions as a professional who uses Python types every day:

    * Some types are better than no types. I love Python types, and I consider them required. Even if they're not type-checked they're better than no types. If they're type-checked it's even better. If things are typed properly (no any etc) and type-checked that's even better. And so on...

    * Having said this, Python's type system as checked by mypy feels like a toy type system. It's very easy to fool it, and you need to be careful so that type-checking actually fails badly formed programs.

    * The biggest issue I face are exceptions. Community discussed this many times [1] [2] and the overall consensus is to not check exceptions. I personally disagree as if you have a Python program that's meticulously typed and type-checked exceptions still cause bad states and since Python code uses exceptions liberally, it's pretty easy to accidentally go to a bad state. E.g. in the linked github issue JukkaL (developer) claims checking things like "KeyError" will create too many false positives, I strongly disagree. If a function can realistically raise a "KeyError" the program should be properly written to accept this at some level otherwise something that returns type T but 0.01% of the time raises "KeyError" should actually be typed "Raises[T, KeyError]".

    * PEP 695 will help because typing things particularly is very helpful. Often you want to pass bunch of Ts around but since this is impractical some devs resort to passing "dict[str, Any]"s around and thus things type-check but you still get "KeyError" left and right. It's better to have "SomeStructure[T]" types with "T" as your custom data type (whether dataclass, or pydantic, or traditional class) so that type system has more opportunities to reject bad programs.

    * Overall, I'm personally very optimistic about the future of types in Python!

    [1] https://github.com/python/mypy/issues/1773

  • Mypy 1.6 Released
    5 projects | news.ycombinator.com | 17 Oct 2023
  • Ask HN: Why are all of the best back end web frameworks dynamically typed?
    4 projects | news.ycombinator.com | 5 Oct 2023
    You probably already know but you can add type hints and then check for consistency with https://github.com/python/mypy in python.

    Modern Python with things like https://learnpython.com/blog/python-match-case-statement/ + mypy + Ruff for linting https://github.com/astral-sh/ruff can get pretty good results.

    I found typed dataclasses (https://docs.python.org/3/library/dataclasses.html) in python using mypy to give me really high confidence when building data representations.

  • Sharing Saturday #472
    7 projects | /r/roguelikedev | 23 Jun 2023
    The in-progress tutorial is here in the official documentation. It sucks that I can never seem to make quick progress on this. Trying to do something clever with Protocols ended up with me making a pull request on the Mypy project for something that likely wasn't critical after all.
  • Writing Python like it's Rust
    10 projects | news.ycombinator.com | 21 May 2023
    I'm also 100% convinced most people who use mypy don't realize the myriad ways it just silently stopps typing things or just silently crashes with a 0 exit code. Even if you configure it to warn untyped functions etc. It will still just not work properly in some of circumstances and you will literally never know until you debug a bug that just happened to trigger it. There are over 1.4k open but tickets it's such a broken piece of software: https://github.com/python/mypy/issues?q=is%3Aissue+is%3Aopen...

    The involvement of Guido in mypy is such a tragedy.

  • Authentication system using Python (Django) and SvelteKit
    7 projects | dev.to | 16 May 2023
    The backend service was built using Django with PostgreSQL database, Redis for session storage, and AWS S3 for file storage. The APIs were built without the use of external REST API frameworks such as Django REST framework. Data serialization and JSON responses were manually handled. Most of the views were made asynchronous. For testing, pytest and its ecosystem were heavily used. Mypy, Pylint and others were used for Static analysis. GitHub Actions were used for automated testing, coverage report and static analysis.
  • Extend Python VENV: Organize Dependencies Your Way
    2 projects | dev.to | 11 May 2023
    Further type checkers like mypy can be used to enable static typing (Python by design is dynamic typing language). Since Python 3.5 typing is a built-in feature. However some additional functionality for typing can be achieved by using typing package (shipped with Python distribution).
  • Mypy is a useless product. Please remove this trash from public use. We don't need it.
    2 projects | /r/programmingcirclejerk | 30 Apr 2023
  • The different uses of Python type hints
    6 projects | news.ycombinator.com | 15 Apr 2023
    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...

What are some alternatives?

When comparing Flake8 and mypy you can also consider the following projects:

Pylint - It's not just a linter that annoys you!

black - The uncompromising Python code formatter [Moved to: https://github.com/psf/black]

pyright - Static Type Checker for Python

autopep8 - A tool that automatically formats Python code to conform to the PEP 8 style guide.

pylama - Code audit tool for python.

autoflake - Removes unused imports and unused variables as reported by pyflakes

prospector - Inspects Python source files and provides information about type and location of classes, methods etc

ruff - An extremely fast Python linter and code formatter, written in Rust.

black - The uncompromising Python code formatter

bandit - Bandit is a tool designed to find common security issues in Python code.

pyre-check - Performant type-checking for python.