Python 3 type hints

Question

Python 3 type hints

cclauss opened this issue 3 years ago · comments

Python type hints would be an interesting direction once Python 2 support is dropped...

$ mypy --ignore-missing-imports .

montydb/montydb/types/_bson.py:279: error: Need type annotation for 'custom_json_hooks' (hint: "custom_json_hooks: Dict[<type>, <type>] = ...")
montydb/montydb/storage/memory.py:14: error: Need type annotation for '_repo'
montydb/montydb/storage/memory.py:15: error: Need type annotation for '_config'
montydb/montydb/storage/memory.py:94: error: Cannot assign to a method
montydb/montydb/storage/memory.py:94: error: Incompatible types in assignment (expression has type "Type[MemoryDatabase]", variable has type "Callable[[AbstractStorage], Any]")
montydb/montydb/storage/memory.py:146: error: Cannot assign to a method
montydb/montydb/storage/memory.py:146: error: Incompatible types in assignment (expression has type "Type[MemoryCollection]", variable has type "Callable[[AbstractDatabase], Any]")
montydb/montydb/storage/memory.py:167: error: Cannot assign to a method
montydb/montydb/storage/memory.py:167: error: Incompatible types in assignment (expression has type "Type[MemoryCursor]", variable has type "Callable[[AbstractCollection], Any]")
montydb/montydb/configure.py:24: error: Need type annotation for '_session' (hint: "_session: Dict[<type>, <type>] = ...")
montydb/montydb/storage/sqlite.py:313: error: Cannot assign to a method
montydb/montydb/storage/sqlite.py:313: error: Incompatible types in assignment (expression has type "Type[SQLiteDatabase]", variable has type "Callable[[AbstractStorage], Any]")
montydb/montydb/storage/sqlite.py:334: error: Argument 1 to "_ensure_table" has incompatible type "Callable[[SQLiteCollection, Any, Any], Any]"; expected "SQLiteCollection"
montydb/montydb/storage/sqlite.py:351: error: Argument 1 to "_ensure_table" has incompatible type "Callable[[SQLiteCollection, Any, Any, Any], Any]"; expected "SQLiteCollection"
montydb/montydb/storage/sqlite.py:414: error: Cannot assign to a method
montydb/montydb/storage/sqlite.py:414: error: Incompatible types in assignment (expression has type "Type[SQLiteCollection]", variable has type "Callable[[AbstractDatabase], Any]")
montydb/montydb/storage/sqlite.py:435: error: Cannot assign to a method
montydb/montydb/storage/sqlite.py:435: error: Incompatible types in assignment (expression has type "Type[SQLiteCursor]", variable has type "Callable[[AbstractCollection], Any]")
montydb/montydb/storage/lightning.py:171: error: Cannot assign to a method
montydb/montydb/storage/lightning.py:171: error: Incompatible types in assignment (expression has type "Type[LMDBDatabase]", variable has type "Callable[[AbstractStorage], Any]")
montydb/montydb/storage/lightning.py:191: error: Argument 1 to "_ensure_table" has incompatible type "Callable[[LMDBCollection, Any, Any, Any], Any]"; expected "LMDBCollection"
montydb/montydb/storage/lightning.py:201: error: Argument 1 to "_ensure_table" has incompatible type "Callable[[LMDBCollection, Any, Any, Any, Any], Any]"; expected "LMDBCollection"
montydb/montydb/storage/lightning.py:241: error: Cannot assign to a method
montydb/montydb/storage/lightning.py:241: error: Incompatible types in assignment (expression has type "Type[LMDBCollection]", variable has type "Callable[[AbstractDatabase], Any]")
montydb/montydb/storage/lightning.py:261: error: Cannot assign to a method
montydb/montydb/storage/lightning.py:261: error: Incompatible types in assignment (expression has type "Type[LMDBCursor]", variable has type "Callable[[AbstractCollection], Any]")
montydb/montydb/storage/flatfile.py:193: error: Cannot assign to a method
montydb/montydb/storage/flatfile.py:193: error: Incompatible types in assignment (expression has type "Type[FlatFileDatabase]", variable has type "Callable[[AbstractStorage], Any]")
montydb/montydb/storage/flatfile.py:220: error: Argument 1 to "_ensure_table" has incompatible type "Callable[[FlatFileCollection, Any, Any], Any]"; expected "FlatFileCollection"
montydb/montydb/storage/flatfile.py:233: error: Argument 1 to "_ensure_table" has incompatible type "Callable[[FlatFileCollection, Any, Any, Any], Any]"; expected "FlatFileCollection"
montydb/montydb/storage/flatfile.py:275: error: Cannot assign to a method
montydb/montydb/storage/flatfile.py:275: error: Incompatible types in assignment (expression has type "Type[FlatFileCollection]", variable has type "Callable[[AbstractDatabase], Any]")
montydb/montydb/storage/flatfile.py:298: error: Cannot assign to a method
montydb/montydb/storage/flatfile.py:298: error: Incompatible types in assignment (expression has type "Type[FlatFileCursor]", variable has type "Callable[[AbstractCollection], Any]")
Found 34 errors in 6 files (checked 100 source files)

David Lai · Answer 1 · Sun Jun 06 2021 02:07:00 GMT+0800 (China Standard Time)

Link this to #27 .
Drop Python 2 support in next minor release.

David Lai · Answer 2 · Sun Jun 06 2021 02:15:29 GMT+0800 (China Standard Time)

Since #28 is on going, maybe we should start this after #28 is merged so to avoid merging conflicts.
But I am not sure when I am able to back on working #28, hopefully in couple weeks.

Jorge Pinto Sousa · Answer 3 · Wed Jul 07 2021 13:48:40 GMT+0800 (China Standard Time)

Can I help on this One?

David Lai · Answer 4 · Wed Jul 07 2021 15:29:41 GMT+0800 (China Standard Time)

Hi @sousajf1 , sure. :)

I am not sure when I can finish #28 so yeah, we should star this one.

Happy to see improvements!

Stephen Eaton · Answer 5 · Wed Jul 07 2021 17:20:09 GMT+0800 (China Standard Time)

seeing you are dropping python 2, I'll remove from dependencies in #57

so supported python versions are 3.7-3.9 ?

David Lai · Answer 6 · Wed Jul 07 2021 17:26:14 GMT+0800 (China Standard Time)

so supported python versions 3.7-3.9 ?

Should be 3.6-3.9, which are versions being tested in Github Actions.

Stephen Eaton · Answer 7 · Wed Jul 07 2021 17:28:53 GMT+0800 (China Standard Time)

so supported python versions 3.7-3.9 ?

Should be 3.6-3.9, which are versions being tested in Github Actions.

hmm I could only see python-version: [ 2.7, 3.7, 3.8, 3.9 ] in your python-package workflow

David Lai · Answer 8 · Wed Jul 07 2021 17:36:38 GMT+0800 (China Standard Time)

Ouch, I was referencing that info from README ! 🤕
Hmmm, Python 3.6 should be supported, it was in the Azure test before I change to use GitHub Action not long ago.

Could you add it back to the workflow ?

David Lai · Answer 9 · Wed Jul 07 2021 18:02:20 GMT+0800 (China Standard Time)

Could you add it back to the workflow ?

Hey @madeinoz67 sorry, never mind, just created #59 to see if Python 3.6 still pass the tests.

Grigory Bakunov · Answer 10 · Mon May 09 2022 09:14:53 GMT+0800 (China Standard Time)

looks like since v2.4.0 is released there are no deal-breakers to add types hinting?

David Lai · Answer 11 · Mon May 09 2022 13:37:13 GMT+0800 (China Standard Time)

Yeah, that's right! 😄

Christian Clauss · Answer 12 · Mon May 09 2022 14:23:38 GMT+0800 (China Standard Time)

It is easier to add type hints if Python 3.6 is dropped because then from __future__ import annotations can be used to substantially reduce the importing of standard data types (ex. Dict, List, Set, Tuple) from the typing module and to enable the more readable list[str | int | None] syntax. That import is only available on Python >= 3.7. Type hints can still be added on Py3.6 but they will be more verbose.