Tips for Working with a Python Development Environment

[kyleburnett]

Install Python and Test Installation

1. Visit https://www.python.org/downloads/ and download the installer for the latest version of Python.
2. Run the installer.
3. Open a terminal and run the following to test your installation:

   python3 --version
   

4. If successful, you should see something like "Python 3.12.0" print to the console.

Set Up a Development Environment

Using virtual environments for Python development is considered best practice because it isolates different (and sometimes conflicting) Python projects from each other. This is helpful for package installation tools like pip. Consider, for instance, two research projects that use the popular tqdm package. Suppose that project A is an older project and uses version 3.8.0 and project B is using version 4.59.0. The system's Python environment and pip package manager cannot maintain both versions of the tqdm package. Therefore, it would be impossible to run project A and project B simultaneously. By creating a virtual environment for each project, however, pip package installs will be placed into the virtual environment in which it was executed.

Note that virtual environments are considered disposable, so don't commit the directory to source control, and don't add files to the virtual environment folder.

Create a virtual environment

Open a terminal. Make sure the current directory is set to the directory of your project and then execute the following to create your virtual environment.

python3 -m venv venv

You should see a new directory called venv has been added to your current directory.

Activate and deactivate an environment

To activate (i.e., "enter into") a virtual environment, run the following command:

source ./venv/bin/activate

To deactivate a virtual environment, run the following:

deactivate

Manage dependencies

It's a good idea to keep pip itself up-to-date, so use the following command when you first create your virtual environment and periodically after that. Note that this should be run inside your virtual environment.

pip install --upgrade pip

You can install other pip packages with the install command. The following example installs the latest versions of proknow and pyclipper:

pip install proknow pyclipper

You can ask for a specific version like this:

pip install proknow==0.19.0

It's a good idea to freeze a list of your package dependencies and their versions to an output file like this:

pip freeze > requirements.txt

This will create the file requirements.txt in your current directory, which should be committed to source control. You should run the freeze command anytime you install, upgrade, or uninstall a package. If your virtual environment is destroyed and recreated at some point or you wish to share your project repository with someone else, you can install the complete list of packages in the requirements.txt like this:

pip install -r requirements.txt