What will the assignments contain?

Homework assignments will mainly involve building out prototypes for applications that we will discuss in class. For example, you will learn to create your own instagram-like filters or snapchat-like masks or smart-car lane detectors.

Each assignment will contain a hw*.ipynb ipython notebook file that will guide you through the homework. This file will ask you to code up functions in other *.py files and may even ask you to fill in short answers or equations in the ipython notebook. All the instructions necessary for the homework are contained in these hw*.ipynb files.

How to submit your assignments?

After you have completed each assignment, you need to submit the following deliverables:

How to start working on an assignment?

Before working on each homework, you need to setup a few things:

Installing Python 3.6+: To use python3, make sure to install version 3.6+ on your local machine. If you are on Mac OS X, you can do this using Homebrew with brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/f2a764ef944b1080be64bd88dca9a1d80130c558/Formula/python.rb . You can find instructions for Ubuntu here .

Setting up a virtual environment: we strongly recommend working using a single virtual environment for all homeworks. This will allow you to have a working environment with all the package dependencies within the repository of your homework, without messing up your work environment in other repositories.

All necessary dependencies for your CS131 homeworks can be found in a single requirements.txt file, which has been placed at the root of the homework release repository.

To set up a virtual environment with name .env , run the following inside your homework directory (ex: inside cs131/ ):

sudo pip install virtualenv        # You will need to do this only once
virtualenv -p python3 .env         # Creates a virtual environment with python3
source .env/bin/activate           # Activate the virtual environment
pip install -r requirements.txt    # Install all the dependencies
# Work on the assignement for a while...
deactivate                         # Exit the virtual environment when you're done

Note that every time you want to work on the assignment, you should run source .env/bin/activate (from within your assignment folder) to re-activate the virtual environment, and deactivate again whenever you are done.

Working with Jupyter notebooks : in your assignment repository, start the notebook with the jupyter notebook command. You might have issues if you are in a virtual environment, as the notebook might not recognize your virtual environment and might not find the kernel located in .env to execute code. In this case, refer to this page and do the following within your virtual environment:

python -m ipykernel install --user --name=my-virtualenv-name

If you are unfamiliar with Jupyter notebooks, you can also refer this IPython tutorial .

When working with a Jupyter notebook, you can edit the *.py files either in the Jupyter interface (in your browser) or with your favorite editor (vim, Atom...). Whenever you save a *.py file, the notebook will reload their content directly.

How do you download the assignments?

All the assignments will be released via github. You can download the files directly from the website. But instead, we recommend, you use git to download the assignments because this will make it easy for you to update the assignments in case there is an update. The instructions below describe how to use git to download our assignments.

1. Installing Git

Follow the instructions here:


2. Downloading the assignments and lecture notes to your local machine.

In terminal, run the following to copy the released homework directory to your desktop.

git clone https://github.com/StanfordVL/CS131_release.git

Run the following to copy the lecture notes directory.

git clone https://github.com/StanfordVL/CS131_notes

3. In case there are updates to the assignments, update your local code using this.

To update your local repository to the newest commit, execute
git pull

This will fetch the changes that TAs made in the remote directory, so your local directory will be up-to-date with the remote one. Be careful that sometimes if the TAs and you are changing the same lines, there will be a conflict, and you may have to fix the conflicts mannually.

In case you did something wrong and want to give up local changes, which hopefully never happens ;), execute

git checkout -- <filename>

Collaboration Policy