Theo Rutter

Getting Started with Python - an Opinionated Guide

August 01, 2023

  1. Download Python

To start, you need to download Python onto your machine. My preferred way to do this is directly via the website. Head to and find your desired version of Python for the operating system you are working with. In my case I’ll download the first option offered to me which happens to be 3.11.4 for MacOS. The download includes an installer which will guide you through the necessary steps to install Python. The installer may provide the option to update the PATH environment variable to include the location of the newly installed Python program - if it does make sure the option is selected.

At this point you should be able to open up the terminal of your choice and execute the command python (or python3 on MacOS/Linux) to start up a Python shell directly from the command line. If this doesn’t work the most likely issues are that Python was not installed successfully, or that it has not been added to the PATH.

  1. Set up a virtual environment

Now that Python is installed, navigate to the directory you will be using to develop your project and create a virtual environment. Different projects may require different packages or versions of Python, so virtual environments are used to create isolated environments for each project. To create a virtual environment, execute the command python3 -m venv .venv. After executing this command you will notice a directory named .venv has been created. To activate the virtual environment, run source .venv/bin/activate on MacOS or .venv/Scripts/activate on Windows. The terminal will indicate that a virtual environment is being used. Now whenever a library is installed it will be associated with the current virtual environment.

  1. Install packages and set up requirements.txt

Depending on the demands of your project you will likely have to install libraries from the internet to provide specific capabilities for your Python programs. To install libraries you can use the pip package manager. For example, you may wish to make http requests in your project using the popular requests module. Run pip install requests to install the library. At any time you can use the pip freeze command to view the libraries that have been installed in your virtual environment.

To create a bill of materials for your Python project with a list of the libraries that are required to run the projects programs, create a file called requirements.txt in your project directory. The requirements file can be used to install all the included libraries in one go using the command pip install -r requirements.txt. Pin the versions of each library to ensure that users of the project are using the correct versions of the necessary libraries.

  1. Set up VSCode

Integrated Development Environments or IDEs are programs dedicated to creating, editing and running software seamlessly. My preference is VSCode which can be downloaded from After downloading and installing VSCode make sure that the code command is added to your PATH variable. This will allow you to navigate to a project directory and run the command code . to open VSCode in that directory. Next install the Python extension for code highlighting and additional features.

  1. Use Jupyter Notebooks

Install the jupyter library and create a file with the .ipynb suffix in your project directory. Now when you open this file in VSCode you should be presented with an interactive notebook interface for creating and running Python code cells. Make sure your virtual environment is being used as the kernel so that all your installed libraries are available to the code running in the notebook.

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Written by Theo Rutter who lives and works in Nottingham. You should check out their github profile.