python3 -m venv /tmp/ruff-verify && /tmp/ruff-verify/bin/pip install -q ruff
/tmp/ruff-verify/bin/ruff --version              # ruff 0.15.12                                                                                                                                                    
/tmp/ruff-verify/bin/ruff check datastore --no-cache --verbose                                                                                                                                                     
# → "Checked 43 files in: 6.735333ms"                                                                                                                                                                              
# → "All checks passed!"                                                                                                                                                                                           
                                                                                                                                                                                                                   
Behaviour parity confirmed:                                                                                                                                                                                        
- 43 datastore/*.py files scanned (matches the count of non-test
.py files in datastore/)                                                                                                                                                                                           
- __init__.py:F401 per-file-ignore correctly applied   
(visible in verbose log)                                                                                                                                                                                           
- datastore/tests/ correctly excluded                                                                                                                                                                              
- Zero findings — same result as the current flake8 datastore run                                                                                                                                                  
                                                                                                                                                                                                                   
Checklist                                                                                                                                                                                                          
                                                       
- No .py source code changes — tooling-only migration                                                                                                                                                              
- Locally verified ruff matches flake8 behaviour on the current
datastore/ (zero findings, see above)                                                                                                                                                                              
- N/A — no DataStore semantics touched                                                                                                                                                                             
- Configuration moved from setup.cfg to pyproject.toml                                                                                                                                                             
[tool.ruff] (consolidates with existing [tool.pyright] and                                                                                                                                                         
[tool.pytest.ini_options])                                                                                                                                                                                         
- No new runtime deps; requirements-dev.txt swaps                                                                                                                                                                  
flake8>=6.0.0 → ruff>=0.5.0                                                                                                                                                                                        
                                                                                                                                                                                                                   
Notes for reviewers                                                                                                                                                                                                
                                                                                                                                                                                                                   
Files changed (4, +27/-22):                                                                                                                                                                                        
 
┌──────────────────────────────┬───────────────────────────────────────────────────────────────────────────────────────────────────────┐                                                                           
│             File             │                                                Change                                                 │
├──────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ pyproject.toml               │ New [tool.ruff] and [tool.ruff.lint] sections; same rule semantics as the previous setup.cfg [flake8] │
├──────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ requirements-dev.txt         │ flake8>=6.0.0 → ruff>=0.5.0                                                                           │                                                                           
├──────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤                                                                           
│ setup.cfg                    │ Removed (only contained [flake8]; nothing else read it in this repo)                                  │                                                                           
├──────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤                                                                           
│ .github/workflows/pr_ci.yaml │ Install + run ruff instead of flake8; comment updated to point at pyproject.toml                      │
└──────────────────────────────┴───────────────────────────────────────────────────────────────────────────────────────────────────────┘                                                                           
                                                       
Follow-up dependency on [AGENTS.md PR](https://github.com/chdb-io/chdb/pull/565): AGENTS.md sections 2.9,                                                                                                                                                   
6.3, 11 and the new PR template checklist all reference flake8 by
name. After both PRs merge, a small doc-only follow-up commit will                                                                                                                                                 
update those references to ruff. Kept out of this PR to keep the                                                                                                                                                   
diff strictly scoped to the tooling change and to avoid conflicting                                                                                                                                                
with the AGENTS.md PR.