STY: remove --keep-runtime-typing from pyupgrade Part-1

[fathomer]

• xref STYLE remove --keep-runtime-typing from pyupgrade #40759
• tests added / passed
• Ensure all linting tests pass, see here for how to run them
• whatsnew entry

[MarcoGorelli]

The mypy failures are due to the fact that some of these methods have their own method type, which interferes with the built-in type

small example:

# t.py

from __future__ import annotations
from typing import Type


class Cat:
    
    def type(self) -> str:
        return 'this is my type'

    def type_cat(self) -> Type[Cat]:
        return Cat

works fine:

$ mypy t.py 
Success: no issues found in 1 source file

but the following:

# t.py

from __future__ import annotations
from typing import Type


class Cat:
    
    def type(self) -> str:
        return 'this is my type'

    def type_cat(self) -> type[Cat]:
        return Cat

doesn't:

$ mypy t.py 
t.py:10: error: Function "t.Cat.type" is not valid as a type
t.py:10: note: Perhaps you need "Callable[...]" or a callback protocol?
Found 1 error in 1 file (checked 1 source file)

If we moved the definitions around so that type_cat came before type, it would work.

---

I think the solution here is to define the alias type_t = type in pandas/_typing.py, and then import that, and use it here. This seems analogous to using bool_t in pandas/core/generic.py (#40175)

cc @WillAyd @simonjayhawkins

EDIT

Actually, using type_t as I'd suggested doesn't work, as then we get

$ mypy t.py 
t.py:12: error: "type" expects no type arguments, but 1 given  [type-arg]
Found 1 error in 1 file (checked 1 source file)

will think of how to do this

---

EDIT2

This seems to work:

in pandas/_typing.py, apply the diff

diff --git a/pandas/_typing.py b/pandas/_typing.py
index f90ef33434..c11cfc0f21 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -25,7 +25,7 @@ from typing import (
     Optional,
     Sequence,
diff --git a/pandas/_typing.py b/pandas/_typing.py
index f90ef33434..c11cfc0f21 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -25,7 +25,7 @@ from typing import (
     Optional,
     Sequence,
     Tuple,
-    Type,
+    Type as Type_t,
     TypeVar,
     Union,
 )
@@ -119,7 +119,7 @@ Axes = Collection[Any]
 # dtypes
 NpDtype = Union[str, np.dtype]
 Dtype = Union[
-    "ExtensionDtype", NpDtype, Type[Union[str, float, int, complex, bool, object]]
+    "ExtensionDtype", NpDtype, Type_t[Union[str, float, int, complex, bool, object]]
 ]
 # DtypeArg specifies all allowable dtypes in a functions its dtype argument
 DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
@@ -187,3 +187,5 @@ ColspaceArgType = Union[
 # internals
 Manager = Union["ArrayManager", "BlockManager"]
 SingleManager = Union["SingleArrayManager", "SingleBlockManager"]

then for any of the lines that are throwing errors, in those files, import Type_t from pandas/_typing.py, and use Type_t instead of type in the problematic annotations

[fathomer]

Thanks @MarcoGorelli for the nice explanation and suggestion, I have made changes according to that and pushed my code.

[MarcoGorelli]

Nice, thanks @fathomer ! Let's wait to hear from the others about this import Type as Type_t workaround

[jreback]

this will get quickly out of date. i would rebase now and we'll see if cna merge it. but maybe better to break into pieces.

confirming this is basically List -> list, Dict -> dict, Tuple -> tuple (can you put the list in the top).

if its more complicated than that we should do in steps.

[jreback]

why not TypeT

[jreback]

or type_t ?

[MarcoGorelli]

you're right, type_t would be more consistent

[fathomer]

So I will change the variable name to type_t, keep the changes to 15-20 files as of now, and still keep the --keep-runtime-typing flag there in precommit hook.
Is that right @MarcoGorelli ?

[MarcoGorelli]

yes, that's right @fathomer! Then, in the final PR, you can remove the flag

[fathomer]

I have reverted changes to all other files except some 20 files for this PR, did a rebase to upstream/master and pushed.
For the remaining files do you want me raise the other PRs just now or wait until this one gets merged ?

[MarcoGorelli]

Thanks @fathomer! You can raise the others now if you want, I'll look over them tomorrow

[fathomer]

@MarcoGorelli @jreback Raised the other PRs as well, for some reason not getting the option to add you guys as reviewers there. Please feel free to review them.

[MarcoGorelli]

Agree on breaking into smaller pieces - if you apply these changes to, say, 15-20 files at a time, then the current check will still pass even if it has --keep-runtime-typing.

If you could break this into a few smaller pull requests, each with no more than 20 files, then we can get those in, and at the end, we can remove --keep-runtime-typing

---

Jeff - the changes here are from PEP585 (e.g. List[str] -> list[str]) and from PEP604 (Optional[str] -> str | None), both of which are only applied in the presence of from __future__ import annotations

[MarcoGorelli]

Looks good, thanks!