We’ve just uploaded mypy 2.1.0 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)).

Mypy is a static type checker for Python. This release includes new features, performance

improvements and bug fixes. You can install it as follows:

python3 -m pip install -U mypy

You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).

The new `librt.vecs` module provides an efficient growable array type `vec` that is

optimized for mypyc use. It provides fast, packed arrays with integer and floating point

value types, which can be **several times faster** than `list`, and tens of times faster

than `array.array` in code compiled using mypyc. It also supports nested `vec` objects and

non-value-type items, such as ``vec[vec[str]]``.

Refer to the [documentation](https://mypyc.readthedocs.io/en/latest/librt_vecs.html) for

the details.

Contributed by Jukka Lehtosalo.

The new `librt.random` module provides fast pseudo-random number generation that is

optimized for code compiled using mypyc. It can be 3x to 10x faster than the stdlib

`random` module in compiled code.

Refer to the [documentation](https://mypyc.readthedocs.io/en/latest/librt_random.html) for

the details.

Contributed by Jukka Lehtosalo (PR [21433](https://github.com/python/mypy/pull/21433)).

- Make compilation order with multiple files consistent (Piotr Sawicki, PR [21419](https://github.com/python/mypy/pull/21419))

- Fix crash on accessing `StopAsyncIteration` (Piotr Sawicki, PR [21406](https://github.com/python/mypy/pull/21406))

- Fix incremental compilation with `separate` flag (Vaggelis Danias, PR [21299](https://github.com/python/mypy/pull/21299))

- Fix crash on partial type with `--allow-redefinition` and `global` declaration (Jukka Lehtosalo, PR [21428](https://github.com/python/mypy/pull/21428))

- Fix broken awaitable generator patching (Ivan Levkivskyi, PR [21435](https://github.com/python/mypy/pull/21435))

- Fix function call error message for small number of arguments (sobolevn, PR [21432](https://github.com/python/mypy/pull/21432))

- Rely on typeshed stubs for `slice` typing (Ivan Levkivskyi, PR [21401](https://github.com/python/mypy/pull/21401))

- Improve negative narrowing for membership checks on tuples (Shantanu, PR [21456](https://github.com/python/mypy/pull/21456))

- Narrow match captures based on previous cases (Shantanu, PR [21405](https://github.com/python/mypy/pull/21405))

- Fix nondeterminism in overload resolution (Shantanu, PR [21455](https://github.com/python/mypy/pull/21455))

- Respect file config comments for stale modules (Adam Turner, PR [21444](https://github.com/python/mypy/pull/21444))

- Fix JSON output mode for syntax errors in parallel mode (Adam Turner, PR [21434](https://github.com/python/mypy/pull/21434))

- Fix type variable with values as a supertype (Ivan Levkivskyi, PR [21431](https://github.com/python/mypy/pull/21431))

- Add support for configuring `--num-workers` with an environment variable (Kevin Kannammalil, PR [21407](https://github.com/python/mypy/pull/21407))

- Respect JSON output mode for syntax errors (Adam Turner, PR [21386](https://github.com/python/mypy/pull/21386))

- Analyze `TypedDict` decorators (Pranav Manglik, PR [21267](https://github.com/python/mypy/pull/21267))

Please see [git log](https://github.com/python/typeshed/commits/main?after=e4d32e01bee44241a5e7c33298c261175b9f1bdb+0&branch=main&path=stdlib) for full list of standard library typeshed stub changes.

Thanks to all mypy contributors who contributed to this release:

- Adam Turner

- Ivan Levkivskyi

- Jukka Lehtosalo

- Kevin Kannammalil

- Piotr Sawicki

- Shantanu

- sobolevn

- Vaggelis Danias

I’d also like to thank my employer, Dropbox, for supporting mypy development.