Assign mode to fromarray

[Erhie]

What did you do?

origPil = Image.open( filename )
origPil_mode = origPil.mode
img_array = np.asarray(origPil)

img_to_show = Image.fromarray( img_array , mode = origPil_mode )
from PIL import ImageShow
ImageShow.show(img_to_show)

What did you expect to happen?

that there is no warning belonging mode in Image.fromarray( img_array , mode = origPil_mode )

What actually happened?

Warning:

Argument of type "str" cannot be assigned to parameter 
"mode" of type
"Literal['1', 'CMYK', 'F', 'HSV', 'I', 'l', "LAB', 'P', 'RGB', 'RGBA', 'RGBX', 'YCbCr'] | None"
in function "fromarray"
   Type "str" cannot be assigned to type 
"Literal['1', "CMYK', 'F', 'HSV', 'I', 'L', 'LAB', 'P', 'RGB', 'RGBA', ''RGBX', 'YCbCr'] | None"

• OS: Windows 10
• Python: Python 3.8
• Pillow: 8.3.2

[radarhere]

Hi. I'm not able to replicate the warning, so here are a few questions.

• What version of numpy are you using? np.__version__.
• I understand that you haven't shown us the import statements and where you are setting filename, but that's it? You're able to reproduce this problem with just this code block in it's own file, without other code that you're written?
• Are you running this from Visual Studio or something like that, rather than from the command line? If you run it from the command line outside of Visual Studio, does the warning go away? I'm not trying to dismiss your problem, just wanting to better understand its origin.

[Erhie]

I use VS Code with extension Pylance
and with further debugging I see there is a prototype for fromarray
def fromarray(obj, mode: _Mode | None = ...) -> Image: ...
and _Mode is defined as
_Mode = Literal["1", "CMYK", "F", "HSV", "I", "L", "LAB", "P", "RGB", "RGBA", "RGBX", "YCbCr"]
Has Pylance generated the file Image.pyi itself?

And numpy has version 1.20.3

[radarhere]

As you've likely gathered, we don't provide typing for fromarray -

Pillow/src/PIL/Image.py

Line 2799 in e122e8f

def fromarray(obj, mode=None):

According to microsoft/pylance-release#659, Pylance comes bundled with .pyi files for PIL, and microsoft/pylance-release#994 was an issue where a user reports a typo in a PIL stub.

However, looking at https://github.com/microsoft/pylance-release/blob/main/CHANGELOG.md, I see that on July 6,

The bundled PIL stubs have been removed, as they have been merged into typeshed's Pillow stubs.

So I think that the problem actually lies in https://github.com/python/typeshed - def fromarray(obj, mode: _Mode | None = ...) -> Image: ...

[radarhere]

@Erhie is that enough information for you to take it from here?

[Erhie]

Thank You!

Now I had success by uninstall and newly installed Pillow and
purge in ....vscode\extensions\ms-python.vscode-pylance-2021.9.1\dist\typeshed-fallback\stubs\Pillow
and now there is no warning for this issue.

For further interests I asked also:
microsoft/pylance-release#1798
and the next step is to ask
https://github.com/python/typeshed