For Python >= 3.11 directly use packaging to compare package versions

[blag]

Description

On Python 3.11 and beyond, pkg_resources no longer bundles packaging:

$ python3.11
Python 3.11.4 (main, Jul 25 2023, 17:35:35)

Type "help", "copyright", "credits" or "license" for more information.
>>> import pkg_resources
>>> pkg_resources.packaging
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'pkg_resources' has no attribute 'packaging'
>>>

That causes this issue in pgcli:

Traceback (most recent call last):
  File ".../bin/pgcli", line 5, in <module>
    from pgcli.main import cli
  File ".../lib/python3.11/site-packages/pgcli/main.py", line 52, in <module>
    from .pgtoolbar import create_toolbar_tokens_func
  File ".../lib/python3.11/site-packages/pgcli/pgtoolbar.py", line 1, in <module>
    from pkg_resources import packaging
ImportError: cannot import name 'packaging' from 'pkg_resources' (unknown location)

So for Python 3.11+, we install the packaging...package, and use it directly:

try:
    from packaging.version import parse as parse_version
except ImportError:
    from pkg_resources.packaging.version import parse as parse_version

Checklist

• I've added this contribution to the changelog.rst.
• I've added my name to the AUTHORS file (or it's already there).

• I installed pre-commit hooks (pip install pre-commit && pre-commit install), and ran black on my code.
• Please squash merge this pull request (uncheck if you'd like us to merge as multiple commits)

[j-bennet]

Hi @blag , thank you for improving pgcli! I see some errors in CI, would you be able to address those? Let me know if you need any help.

[dbaty]

This is only used to detect the version of prompt_toolkit in the following block :

vi_modes = {
    InputMode.INSERT: "I",
    InputMode.NAVIGATION: "N",
    InputMode.REPLACE: "R",
    InputMode.INSERT_MULTIPLE: "M",
}
if parse_version(prompt_toolkit.__version__) >= parse_version("3.0.6"):
    vi_modes[InputMode.REPLACE_SINGLE] = "R"

We could surely check the existence of InputMode.REPLACE_SINGLE instead of explictly checking the version? Something like this:

vi_modes = {...}
if "REPLACE_SINGLE" in {e.name for e in InputMode}:  # available in prompt_toolkit >= 3.0.6 
    vi_modes[InputMode.REPLACE_SINGLE] = "R"

(or use a try/except clause, or InputMode._member_names_ if we're feeling slightly adventurous...)

[blag]

@j-bennet CI run now needs approval. But I removed packaging from setup.py, so the dependency installation issues should now be moot.

@dbaty Thanks for the fleshed-out suggestion, I went with it.

[codecov-commenter]

Codecov Report

Patch coverage: 51.70% and project coverage change: -4.66% ⚠️

Comparison is base (6884c29) 84.15% compared to head (05d0cc2) 79.50%.
Report is 61 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1416      +/-   ##
==========================================
- Coverage   84.15%   79.50%   -4.66%     
==========================================
  Files          21       25       +4     
  Lines        2720     2981     +261     
==========================================
+ Hits         2289     2370      +81     
- Misses        431      611     +180     

Files Changed	Coverage Δ
pgcli/completion_refresher.py	91.76% <ø> (+1.17%)	⬆️
pgcli/magic.py	0.00% <0.00%> (ø)
pgcli/packages/parseutils/tables.py	97.67% <ø> (ø)
pgcli/packages/sqlcompletion.py	97.67% <ø> (ø)
pgcli/pgcompleter.py	96.95% <ø> (ø)
pgcli/pgstyle.py	64.00% <ø> (ø)
pgcli/pyev.py	15.38% <15.38%> (ø)
pgcli/pgtoolbar.py	25.71% <20.00%> (-5.72%)	⬇️
pgcli/explain_output_formatter.py	46.15% <46.15%> (ø)
pgcli/key_bindings.py	52.94% <66.66%> (-0.19%)	⬇️
... and 8 more

... and 1 file with indirect coverage changes

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[j-bennet]

Looks good @blag , merging. 👍