Initialize the variable `n_cols_added` #78

	name: lint

	on:
	pull_request:
	push:
	branches:
	- main

	jobs:
	lint:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	with:
	fetch-depth: 2
	- name: Set up Python
	uses: actions/setup-python@v3
	with:
	python-version: "3.10"
	- name: Install pre-commit hooks
	run: \|
	pip install -U pip==23.1.0
	pip install -U pre-commit==3.4.0
	pre-commit install
	- name: Run pre-commit hooks
	run: \|
	pre-commit run --all-files

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