CS50 web, Ubuntu, pyenv and submit50 - but I'm a Windows girl...

I’ve recently started to follow CS50 for Web. Because why not, I have a week of free time between jobs, and I planned to do it for some time. Watching lectures is fun (while knitting, for example), but when I hit Django lecture I started to follow along. First of all, I’m a frontend dev using a Windows machine (Win11) and I try not to touch Linux until absolutely necessary. To follow a Django lecture, I had to install Django, and to install Django I had to install Python. But I didn’t want any Python, to me it’s logical that if there are multiple versions of something, there should be a version manager. Like for Node, there is nvm. After some googling it turned out there is pyenv and even a Windows version called pyenv-win. And there is a nice tutorial for that at https://pyenv-win.github.io/pyenv-win/docs/installation.html.

I installed pyenv-win, I installed Django, I followed the lecture. Nice! Btw Django is awesome, it may look scary because it’s using templates (a concept in which I haven’t developed anything yet, but I am familiar with the syntax, I even wrote a bit about Twig - a template engine for PHP (I had to learn it for work, but haven’t used it in the end. The article/tutorial/introduction to Twig is here).

Watching lectures and coding along with a demonstration is nice, but at some point one has to work on a project. And if one wants to earn a verified certificate with an official stamp from Harvard University (I am one, I want such a cert), one has to submit the required projects that meet the required criteria. For this, after coding the Project 0 (which, btw, I pushed to my GitHub repo first), I had to figure out how to submit it for grading. The instructions told me to install submit50, to make things easier. And what’s the first thing I see? To use Linux and install Ubuntu, like a proper human person, not a Windows normie… I’m both gaming and developing on my personal machine, I don’t want to ditch Windows… But WSL comes to the rescue. And with the newer WSL2 version (from Win11) it apparently has a dedicated Linux kernel (I don’t really know what it means, but it sounds professional). And I have already installed WSL on another machine, where I had to set up a dev environment for a big project at work. Seems easy, so let’s do it.

Problem: Install Python, pip and pyenv on a Windows machine using WSL, while keeping Windows versions intact (pyenv-win, Python installed on Windows, pip installed on Windows) so that they don’t clash

Starting point: Win11

Goal: be able to use submit50

Steps:

1. Installing WSL and Ubuntu

• First, install WSL and Ubuntu, following the official docs: https://learn.microsoft.com/en-us/windows/wsl/install

• Restart the system

• Open Ubuntu: open terminal and enter wsl -d Ubuntu

2. Installing pyenv

• Install pyenv following this tutorial: https://realpython.com/intro-to-pyenv/#installing-pyenv (also make sure that your system is updated before doing that (sudo apt update)

• Verify that pyenv was correctly installed by running pyenv --version

And if you have a pyenv-win installed, here is a potential issue. In my case pyenv was trying to execute the Windows version pyenv-win using Windows commands cygpath and cmd:

And that’s not what I want.

By running which pyenv I verified that indeed it is looking in the Windows file system:

Steps to fix this and point my Linux pyenv to correct executable while keeping my Windows version of pyenv-win intact:

• Edit ~/.bashrc by typing nano ~/.bashrc in the terminal

• Add those lines at the end of the file:

•   export PYENV_ROOT="$HOME/.pyenv"
    export PATH="$PYENV_ROOT/bin:$PATH"
    eval "$(pyenv init --path)"
  

• Save the file (CTRL + X, then Y, then Enter).

• Reload your shell by typing source ~/.bashrc

• Verify the pyenv location and version again:

3. Installing Python and pip

Find what is the latest stable Pythin release at https://www.python.org/downloads/. Similarly, check what is the LTS for pip https://pypi.org/project/pip/. Because I have both aleady installed, but on Windows, I run into a similar issue as with pyenv:

It is using the Windows version. Because my bashrc profile already contains the path for pyenv, it should be pointing to the correct pyenv version. But it isn’t. I found that adding another line at the end of the file solved the problem. Add this line to ensure that WSL does not point to Windows pyenv-win: export PATH=$(echo "$PATH" | sed -e 's|/mnt/c/Users/wojew/.pyenv/pyenv-win[^:]*:||g')

To do this, edit your bash profile similarly to the steps above. So, to repeat for clarity:

• Type nano ~/.bashrc in the terminal

• Scroll down and add this line to the end of the file: export PATH=$(echo "$PATH" | sed -e 's|/mnt/c/Users/wojew/.pyenv/pyenv-win[^:]*:||g')

• Save the file (CTRL + X, then Y, then Enter).

• Reload your shell by typing source ~/.bashrc

• Now verify pip and python installation on WSL using the commands: pyenv which pip and pyenv which python. On my machine it is not finding the commands, meaning the Windsows installation is not being recognized anymore and I successfully separated them:

Now I need to install pip and Python on WSL using pyenv.

LTS for Python as I write it is 3.13.2 and for pip it is 25.0.1. Let’s install them using pyenv:

Set it as global with pyenv global 3.13.2. Verify with python --version that this Python is actually being used and correctly installed. Now let’s check pip. When installing pyenv, pip should be installed automatically. Let’s verify which version is installed with pip —version:

Since I haven’t worked on any projects yet, let’s upgrade pip to LTS, using python -m pip install --upgrade pip==25.0.1:

Verify that it is currenlty using the desired pip version.

Now that everything is set up, I can finally submit my Project 0 code for grading using submit50! It took me only… 2 hours of faffing about ;)

4. Submitting work with submit50 - but first you need to install it

To install submit50 using pyenv-managed version of Python, first check where pip is located using which pip3. If it points to /usr/bin/pip3, it’s installing system-wide, bypassing pyenv. If it’s pointing to /home/[username]/.pyenv/, it is using pyenv. The correct way of using pyenv to install packages is:

pyenv exec pip install submit50
or
python -m pip install submit50

However, I run into issues. Rust and Cargo were needed to compile it… At this point I started to question all my choices because I don’t know what I’m doing anymore. Thankfully ChatGPT helped me figure out what to do about it.

Hint: See above for details. Eh. ChatGPT says “This means the package jellyfish (a dependency of submit50) requires Rust to compile, but Rust is missing in your WSL environment“. Fair. I’ll just provide a screenshot:

So I installed Rust and Cargo to be able to use submit50. Great. Re-running the installation was successfull. Hurray!

Now I can finally follow the instructions at https://cs50.readthedocs.io/submit50/#submitting-with-submit50 to submit my work.

…and I did all that, only to find out that submit50 doesn’t work anymore and it is easier to just use git…

yay coding!