Add virtual env, CLASSIC method

python -m venv env

source env/bin/activate

pip install Flask

python -m pip freeze > requirements.txt

Install from requirements.txt:

pip install -r requirements.txt

Add virtual env, with POETRY

pip install poetry

Create or init existings project:

poetry new <project_name> or poetry init

Create lock:

poetry lock

To Activate ENV: source $(poetry env info --path)/bin/activate

To Deactivate ENV: deactivate

Examples poetry commands:

poetry add aiosqlite

poetry remove aiosqlite

poetry install

poetry update

poetry show

poetry run pytest

poetry export --without-hashes --format=requirements.txt > requirements.txt

-= Example Makefile for poetry =-

Since you we are using poetry, there is no need to manually activate the virtual environment, poetry run automatically runs commands in it

.PHONY: setup \
        lint \
        mypy \
        help

setup: ## Project setup
    poetry install

lint: ## Run linter
    poetry run ruff format --config ./pyproject.toml .
    poetry run ruff check --fix --config ./pyproject.toml .

mypy: ## Run mypy
    poetry run mypy ./

test: ## Run tests check
    poetry run pytest $(filter-out $@,$(MAKECMDGOALS)) -s

# Just help
help: ## Display help screen
    @grep -h -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'```