So, I have a python script I’d like to run from time to time from the CLI (on Linux) that resides inside a venv. What’s the recommended/intended way to do this?
Write a wrapper shell script and put it inside a $PATH-accessible directory that activates the virtual environment, runs the python script and deactivates the venv again? This seems a bit convoluted, but I can’t think of a better way.

  • Andy
    2·
    6 months ago

    I use my own Zsh project (zpy) to manage venvs stored like ~/.local/share/venvs/HASH-OF-PROJECT-PATH/venv, so use zpy’s vpy function to launch a script with its associated Python executable ad-hoc, or add a full path shebang to the script with zpy’s vpyshebang function.

    vpy and vpyshebang in the docs

    If anyone else is a Zsh fan and has any questions, I’m more than happy to answer or demo.

    • Faulkmore@mastodon.social
      1·
      6 months ago

      @Andy The convention is to place the venv in a .venv/ sub folder. Follow the convention!

      This is shell agnostic

      Learn pyenv and minimize shell scripts (only lives within a Makefile).

      Shell scripts within Python packages is depreciated

      • Andy
        2·
        6 months ago

        The convention

        That’s one convention. I don’t like it, I prefer to keep my venvs elsewhere. One reason is that it makes it simpler to maintain multiple venvs for a single project, using a different Python version for each, if I ever want to. It shouldn’t matter to anyone else, as it’s my environment, not some aspect of the shared repo. If I ever needed it there for some reason, I could always ln -s $VIRTUAL_ENV .venv.

        Learn pyenv

        I have used pyenv. It’s fine. These days I use mise instead, which I prefer. But neither of them dictate how I create and store venvs.

        Shell scripts within Python packages is depreciated

        I don’t understand if what you’re referencing relates to my comment.

        • logging_strict
          1·
          6 months ago

          The multiple venv for different Python versions sounds exactly like what tox does

          Then setup a github action that does nightly builds. Which will catch issues caused by changes that only tested against one python version or on one platform

          py313 is a good version to test against cuz there were many modules removed or depreciated or APIs changed

          good luck. Hope some of my advice is helpful

          • Andy
            2·
            6 months ago

            Thanks, yes, I use nox and github actions for automated environments and testing in my own projects, and tox instead of nox when it’s someone else’s project. But for ad hoc, local and interactive multiple environments, I don’t.

            • logging_strict
              1·
              2 months ago

              thanks for the head up on nox. Syntax seems like a tox meets pytest.

            • logging_strict
              1·
              2 months ago

              Are you using github actions locally? Feel silly making gh actions and workflows and only github runs them

              • Andy
                1·
                2 months ago

                No, I don’t use GHA locally, but the actions are defined to run the same things that I do run locally (e.g. invoke nox). I try to keep the GHA-exclusive boilerplate to a minimum. Steps can be like:

                - name: fetch code
  uses: actions/checkout@v4

- uses: actions/setup-python@v5
  with:
    allow-prereleases: true
    python-version: |
      3.13
      3.12
      3.11
      3.10
      3.9
      3.8
      3.7

- run: pipx install nox

- name: run ward tests in nox environment
  run: nox -s test test_without_toml combine_coverage --force-color
  env:
    PYTHONIOENCODING: utf-8

- name: upload coverage data
  uses: codecov/codecov-action@v4
  with:
    files: ./coverage.json
    token: ${{ secrets.CODECOV_TOKEN }}

                Sometimes if I want a higher level interface to tasks that run nox or other things locally, I use taskipy to define them in my pyproject.toml, like:

                [tool.taskipy.tasks]
fmt = "nox -s fmt"
lock = "nox -s lock"
test = "nox -s test test_without_toml typecheck -p 3.12"
docs = "nox -s render_readme render_api_docs"
                • logging_strict
                  1·
                  2 months ago

                  Thanks for the introduction to taskipy. Think if i need macros, Makefile is the way to go. Supports running targets in parallel and i like performing a check to ensure the virtual environment is activated or the command won’t run.

                  .ONESHELL:
.DEFAULT_GOAL := help
SHELL := /bin/bash
APP_NAME := logging_strict

#virtual environment. If 0 issue warning
#Not activated:0
#activated: 1
ifeq ($(VIRTUAL_ENV),)
$(warning virtualenv not activated)
is_venv =
else
is_venv = 1
VENV_BIN := $(VIRTUAL_ENV)/bin
VENV_BIN_PYTHON := python3
PY_X_Y := $(shell $(VENV_BIN_PYTHON) -c 'import platform; t_ver = platform.python_version_tuple(); print(".".join(t_ver[:2]));')
endif

.PHONY: mypy
mypy:					## Static type checker (in strict mode)
ifeq ($(is_venv),1)
	@$(VENV_BIN_PYTHON) -m mypy -p $(APP_NAME)
endif

                  make mypy without the virtualenv on will write a warning message why it’s not working!

                  • Andy
                    1·
                    2 months ago

                    Sure, but nox is the closer counterpart for in-venv-task definitions. List “sessions” with -l, pick specific sessions to run with -s.

                    import nox
from nox.sessions import Session

nox.options.reuse_existing_virtualenvs = True
APP_NAME = 'logging_strict'

@nox.session(python='3.12')
def mypy(session: Session):
    """Static type checker (in strict mode)"""
    session.install('-U', 'mypy', '.')
    session.run('mypy',  '-p', APP_NAME, *session.posargs)

                    Unfortunately it doesn’t currently do any parallel runs, but if anyone wants to track/encourage/contribute in that regard, see nox#544.