It all started a Saturday morning, when I came cross this LinkedIn post over coffee ☕

The post is about the always interesting and spicy topic of python packaging pain 🤪

The article recommended in the post is hilarious 🤣 and definately worth a read. I am saving it here so I can read it again. (link: Why not tell people to "simply" use pyenv, poetry or anaconda)

Anyway, back to the tool recommended in the article, which is venv. 😎 I only used vevn very briefly at the beginning of my python journey, then moved on to tools like pipenv and anaconda which the article critisized about. In the name of fun and exploration, let me do venv again and document my learning on the way. I will follow the instruction from the official venv doc and do my best not to "stackoverflow my way out of suffering" (To be honest, I can't remember how many times stackoverflow saved my life ❤️)

This repo seeks to accomplish three things.

1. Create the .venv using a particular python version ✅
2. Active and use the .venv ✅
3. Share the virtual environment so others can reproduce it ✅

Pls see below the detailed tested steps (including some troubleshooting 🔧 tips). Feel free to try it yourself and let me know how you go. 🤩 Good luck! 🤞

• I have multiple python versions available in anaconda, but lets don't use it for this experiment.
• Check the default Global python version: python --version.
  • find path to it:
  • run python -c "import os, sys; print(os.path.dirname(sys.executable))", or
  • run python -m identify_python_path while in this repo's root folder
• How do I find out about other Pythons versions available in my machine?
  • typically for windows it is saved in C:\Users\<username>\AppData\Local\Programs\Python\Python3X
  • or run py --list-paths

• Check whether the desired python version is available.
• If not, install using the official installer at python.org, for example windows installer available here
• After installation, run the command below (for windows) C:\Users\<username>\AppData\Local\Programs\Python\Python3X\python -m venv PATH-to-REPO\.venv
  • one could also use py -3.x -m venv to specify python version but I opted to specify where exactly this python sits, since py --lists-paths give me interesting results due to my installation history. 🙈
• This is where I used to stumble before.
  • If I don't specify the path to the particular python version, it would always just used the default.
  • If I revise the environment path variable to prioritize this desired python version, it would then become the new default.
  • In contrast, the solution above gives us the flexibility to create a .venv with whichever python version we see fit for each particular project.

• Following the instruction from official venv doc, you can activate the environment using .venv/Scripts/activate (windows)
  • In windows you could have this error: .venv/Scripts/activate : File path-to-project\.venv\Scripts\Activate.ps1 cannot be loaded because running scripts is disabled on this system.
  • In this case, run Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
• python -m pip install any pakcages needed (Why not pip install directly? 🧐 here is a discussion)

• To export the environment
  • Freeze the environemnt for the project using python -m pip freeze > requirements_py310.txt
  • One of the important reasons that I switched from venv to pipenv was because python version was natually specified in pipenv's lockfile Pipfile.lock. But this is not the case with requimrenets.txt.
  • Fortunately as shown above, it is pretty straightforward to utilize specific python versions for venv implementations too, one just need to be mindful and specify it while creating the environment.
  • Therefore, I personaly prefer to specify python version at the title of the requirements like requirements_py3xx, which can serve as a reminder to myself and everyone who wants to replicate the environment re: which python version is needed for this venv.
• To replicate the environment
  • Create the venv with the specific version (see step 1 above)
    • if exist already, run Remove-Item -Path ".venv" -Recurse -Force in powershell
  • Activate the venv (see step 2 above)
  • then python -m pip install -r requirements_py310.txt