We’ve just uploaded mypy 2.1.0 to the Python Package Index (PyPI). 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.
librt.vecs: Fast Growable Array Type for Mypyc
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 for the details.
Contributed by Jukka Lehtosalo.
librt.random: Fast Pseudo-Random Number Generation
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 for the details.
Contributed by Jukka Lehtosalo (PR 21433).
Mypyc Improvements
- Make compilation order with multiple files consistent (Piotr Sawicki, PR 21419)
- Fix crash on accessing StopAsyncIteration (Piotr Sawicki, PR 21406)
- Fix incremental compilation with separate flag (Vaggelis Danias, PR 21299)
Fixes to Crashes
- Fix crash on partial type with --allow-redefinition and global declaration (Jukka Lehtosalo, PR 21428)
- Fix broken awaitable generator patching (Ivan Levkivskyi, PR 21435)
Changes to Messages
- Fix function call error message for small number of arguments (sobolevn, PR 21432)
Other Notable Fixes and Improvements
- Rely on typeshed stubs for slice typing (Ivan Levkivskyi, PR 21401)
- Improve negative narrowing for membership checks on tuples (Shantanu, PR 21456)
- Narrow match captures based on previous cases (Shantanu, PR 21405)
- Fix nondeterminism in overload resolution (Shantanu, PR 21455)
- Respect file config comments for stale modules (Adam Turner, PR 21444)
- Fix JSON output mode for syntax errors in parallel mode (Adam Turner, PR 21434)
- Fix type variable with values as a supertype (Ivan Levkivskyi, PR 21431)
- Add support for configuring --num-workers with an environment variable (Kevin Kannammalil, PR 21407)
- Respect JSON output mode for syntax errors (Adam Turner, PR 21386)
- Analyze TypedDict decorators (Pranav Manglik, PR 21267)
Typeshed Updates
Please see git log for full list of standard library typeshed stub changes.
Acknowledgements
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.
