`py.typed` present, but not all methods have types about pillow

[radarhere]

Out of curiosity, I got the current main branch of Pillow and added

[tool.mypy]
disallow_untyped_defs = true

to pyproject.toml. There's quite a lot of untyped defs:

Found 853 errors in 58 files (checked 102 source files)

As a progress update, that number is now halved - we're down to

Found 421 errors in 40 files (checked 102 source files)

[radarhere]

We're now down to

Found 97 errors in 16 files (checked 283 source files)

[radarhere]

Pillow 10.4.0 has now been released, with type hints for all of the methods explicitly mentioned in this issue.

[johnthagen]

@radarhere 10.4.0 allowed us to remove a lot of type: ignore statements, thanks! ❤️

In our particular codebase, the only remaining untyped call we hit after upgrading to 10.4.0 is:

Pillow/src/PIL/ImageTk.py

Line 99 in 8c26622

def __init__(self, image=None, size=None, **kw):

[radarhere]

If you're happy with that, great! However, the OP wanted us to meet a different standard - not showing any errors when disallow_untyped_defs = true was enabled.

With that setting, we're still at

Found 57 errors in 11 files (checked 283 source files)

[radarhere]

While I don't feel comfortable making the decision to remove py.typed myself, I can help add further type hints. I've created #8030 to add verify(), draft() and _expand() (I think you meant this, as ImageOps.expand() is already typed in 10.3.0).

Edit: I've created #8042 for filter().

#8032 has been created to add type hints for load().

I know that to a certain extent, these were just examples you were mentioning, and there is plenty more work to go.

we call PIL.Image.Image.open() which (among many other function) is untyped

This should already be partially type hinted in 10.3.0.

Pillow/src/PIL/Image.py

Line 3225 in 5c89d88

def open(fp, mode="r", formats=None) -> Image:

Thanks to #7944, that has been improved in main.

Pillow/src/PIL/Image.py

Lines 3250 to 3254 in ddbf08f

	def open(
	fp: StrOrBytesPath | IO[bytes],
	mode: Literal["r"] = "r",
	formats: list[str] | tuple[str, ...] | None = None,
	) -> ImageFile.ImageFile:

One example of a function missing type hints is from PIL.Image.fromarray.

This has actually already been added to main in #7936

The next release of Pillow is scheduled for July 1st, so if there are any more specific methods you would like to see typed before then, feel free to request them.

[radarhere]

#8191 has now typed that method.

[johnthagen]

We hit a large number of new Mypy issues when we upgraded to Pillow 10.3.0, to the point where we may pin to 10.2.0 until they are addressed and all the missing type hints added (or py.typed is removed until this is done).

Some of the errors can be suppressed in the Mypy config:

[tool.mypy]
untyped_calls_exclude = [
    "PIL",
]

One example of a function missing type hints is PIL.Image.fromarray.

[hugovk]

I'd like to propose a PR, but I'm afraid I don't have the time to work on such a large change. Even the Image class has quite a lot of untyped methods (load(), verify(), draft(), expand(), filter(), and many others).

Smaller PRs are very welcome and also preferred, they're easier to review and quicker to merge.

[akx]

Looks like

Success: no issues found in 283 source files

to me on 71876cf :)

[akx]

Ah, I thought we were going with what make mypy checks. My bad!

[johnthagen]

To avoid regressions, I'd recommend turning this on in this repo once the remaining missing types are fixed.