changes done in 4th april introduced a regression

[categulario]

Describe the bug

Error details
I updated fpdf to 2.5.2 (latest at the moment of writing) while keeping pillow in 7.0.0. Code that was working no longer is because commit 4acaaec introduced a dependency on enums added in pillow==9.1.0 (python-pillow/Pillow#5954).

here is the traceback

  File "project/.venv/lib/python3.8/site-packages/fpdf/fpdf.py", line 265, in wrapper
    return fn(self, *args, **kwargs)
  File "project/.venv/lib/python3.8/site-packages/fpdf/fpdf.py", line 3131, in image
    info = self._downscale_image(name, img, info, w, h)
  File "project/.venv/lib/python3.8/site-packages/fpdf/fpdf.py", line 3261, in _downscale_image
    info = get_img_info(
  File "project/.venv/lib/python3.8/site-packages/fpdf/image_parsing.py", line 50, in get_img_info
    img = img.resize(dims, resample=Image.Resampling.LANCZOS)
  File "project/.venv/lib/python3.8/site-packages/PIL/Image.py", line 62, in __getattr__
    raise AttributeError("module '{}' has no attribute '{}'".format(__name__, name))
AttributeError: module 'PIL.Image' has no attribute 'Resampling'

Minimal code

I just called pdf.image() really. As mentioned earlier, the code was working, now it is not.

Environment

• Linux
• pytthon 3.8
• fpdf2 2.5.2

Problem is introduced in:

https://github.com/PyFPDF/fpdf2/blob/master/fpdf/image_parsing.py#L50

[Lucas-C]

Hi @categulario and thanks for reporting this.

I don't think we have really discussed this before,
but fpdf2 is expected to work with the latest version of Pillow, not necesseraliy all versions of Pillow.

Can't you simply upgrade your version of Pillow?

If you really have a need to use pillow==7.0.0, I think we can make fpdf2 compatible.
Feel free to submit a PR if you wish

[categulario]

Ok, I updated pillow to 9.1.0 and now the code works.

What can be done in this kind of situation? update setup.py to reflect compatible version of pillow? add testing with a matrix of versions of pillow?

will close for now, but I suspect I'm not the only one, I'm just the one reported it first...

[Lucas-C]

What can be done in this kind of situation?

It depends a lot on your usage...
Usually I would recommend dependency locking, for example using poetry.
This kind of tool provides commands for upgrading your dependencies "intelligently".

But for basic usage, pip install --upgrade should be enough:

pip install --upgrade $path/to/python/project/dir   # containing a setup.py or setup.cfg
# or
pip install --upgrade -r requirements.txt

Those commands will upgrade all yours dependencies at once,
and hence you would not have face the error you got by only upgrading fpdf2

[Lucas-C]

On second thought, you were right, I was missing something:
I added a minimum Pillow version in setup.py: https://github.com/PyFPDF/fpdf2/blob/master/setup.py#L36

[categulario]

;) 🙏🏽