Python tidy and formatter #25

	name: Python Lint and Format Check

	on:
	pull_request:
	branches:
	- develop
	- 'release/**'
	paths:
	- "mlir/**"
	- "external/**"
	- "!external/llvm-project/**"
	push:
	branches:
	- develop
	- 'release/**'
	paths:
	- "mlir/**"
	- "external/**"
	- "!external/llvm-project/**"
	jobs:
	py-checks:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	with:
	fetch-depth: 0

	- name: Set up Python
	uses: actions/setup-python@v5
	with:
	python-version: '3.8'

	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install flake8 yapf pep8-naming

	- name: Get changed Python files under mlir/
	id: changes
	shell: bash
	run: \|
	BASE_SHA="${{ github.event.pull_request.base.sha }}"
	HEAD_SHA="${{ github.sha }}"
	# list added/modified files, restrict to mlir/*/.py
	files=$(git diff --name-only --diff-filter=AM "$BASE_SHA" "$HEAD_SHA" \
	\| grep -E '^mlir/.*\.py$' \|\| true)
	echo "files<<EOF" >> $GITHUB_OUTPUT
	echo "$files" >> $GITHUB_OUTPUT
	echo "EOF" >> $GITHUB_OUTPUT
	echo "Changed files:"
	echo "$files"

	- name: Run flake8
	if: steps.changes.outputs.files != ''
	run: \|
	flake8 ${{ steps.changes.outputs.files }}

	- name: Run YAPF check
	if: steps.changes.outputs.files != ''
	run: \|
	# --diff prints a unified diff and returns non-zero if changes would be made
	yapf --diff ${{ steps.changes.outputs.files }} \
	\|\| (echo "Format issues found. Fix locally with: yapf -i <files>"; exit 1)

	- name: No Python changes in mlir/
	if: steps.changes.outputs.files == ''
	run: echo "No changed *.py files under mlir/ – skipping."

Provide feedback