'cached_property' from 'functools' - seems incompatible with python3.7

[RobWatersMet]

Describe the bug
Installed via conda-forge with python 3.7

ImportError: cannot import name 'cached_property' from 'functools' (/home/rob/miniconda3/envs/sat_rgb/lib/python3.7/functools.py)

To Reproduce
conda create -n test python=3.7
conda install -c conda-forge satpy

from satpy.readers import load_readers

Expected behavior
enforce python >=3.8 in setup.py rather than 3.7

Actual results

(sat_rgb) rob@MS009899:~/code/enhanced_rgb/ensat$ python
Python 3.7.13 (default, Mar 29 2022, 02:18:16)
[GCC 7.5.0] :: Anaconda, Inc. on linux
Type "help", "copyright", "credits" or "license" for more information.

from satpy.readers import load_readers
Traceback (most recent call last):
File "", line 1, in
File "/home/rob/miniconda3/envs/sat_rgb/lib/python3.7/site-packages/satpy/init.py", line 35, in
from satpy.multiscene import MultiScene # noqa
File "/home/rob/miniconda3/envs/sat_rgb/lib/python3.7/site-packages/satpy/multiscene.py", line 32, in
from satpy.scene import Scene
File "/home/rob/miniconda3/envs/sat_rgb/lib/python3.7/site-packages/satpy/scene.py", line 36, in
from satpy.readers import load_readers
File "/home/rob/miniconda3/envs/sat_rgb/lib/python3.7/site-packages/satpy/readers/init.py", line 37, in
from .yaml_reader import AbstractYAMLReader
File "/home/rob/miniconda3/envs/sat_rgb/lib/python3.7/site-packages/satpy/readers/yaml_reader.py", line 40, in
from functools import cached_property
ImportError: cannot import name 'cached_property' from 'functools' (/home/rob/miniconda3/envs/sat_rgb/lib/python3.7/functools.py)

Environment Info:

• OS: Linux
• Satpy Version: 0.37.1 pyhd8ed1ab_0 conda-forge
• PyResample Version: 1.23.0 py37hfb7772e_1 conda-forge

[pnuu]

Python 3.7 support was dropped in May 27, 2022 with 90ceb73

It seems that the conda-forge recipe still has >=3.7 in it: https://github.com/conda-forge/satpy-feedstock/blob/main/recipe/meta.yaml#L25

Ping @djhoese

[djhoese]

Yeah looks like there are two releases on conda-forge that need to be removed then...darn. I'm not sure conda-forge's preferences for removing builds just for version limits. I'll read up on it today hopefully.

[djhoese]

I also don't know if conda-forge technically supports Python 3.7 anymore.

[djhoese]

Ah they dropped it 10 days ago:

https://conda-forge.org/docs/user/announcements.html#dropping-python-3-7

I'm guessing that means that the packages will just stop being generated for Python 3.7.

[djhoese]

FYI there is a new build on conda-forge with the correct version limits. I'm still looking into patching the old releases with the bad version limit.

conda-forge/satpy-feedstock#54

[djhoese]

This PR will patch the necessary metadata if/when it is merged by conda-forge admins: conda-forge/conda-forge-repodata-patches-feedstock#334

[pnuu]

Closing, conda-forge/conda-forge-repodata-patches-feedstock#334 has been merged.