refactor: simplify expr checking in predicate push down #3

	name: Lint Python

	on:
	pull_request:
	paths:
	- py-polars/**
	- .github/workflows/lint-python.yml

	concurrency:
	group: ${{ github.workflow }}-${{ github.ref }}
	cancel-in-progress: true

	jobs:
	lint-python:
	runs-on: ubuntu-latest
	defaults:
	run:
	working-directory: py-polars

	steps:
	- uses: actions/checkout@v4

	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: '3.11'

	- name: Install Python dependencies
	run: pip install -r requirements-lint.txt

	- name: Lint Python
	run: \|
	ruff check --diff .
	ruff format --diff .
	blackdoc --diff .

	mypy:
	runs-on: ubuntu-latest
	strategy:
	fail-fast: false
	matrix:
	python-version: ['3.8', '3.11']
	defaults:
	run:
	working-directory: py-polars

	steps:
	- uses: actions/checkout@v4

	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}

	- name: Install dependencies
	run: \|
	pip install -r requirements-dev.txt
	pip install -r requirements-lint.txt

	# Allow untyped calls for older Python versions
	- name: Run mypy
	run: mypy ${{ (matrix.python-version == '3.8') && '--allow-untyped-calls' \|\| '' }}

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