If you regularly use Python and its libraries from the terminal or in your shell scripts, adding Python to the systems PATH variable becomes essential. When you run Python for the first time after installation, your command may return an error or launch a different Python version from the one you downloaded. Once you add Python to PATH, it eliminates the hassle of entering the full path to the Python executable all the time. If you run into a “command not found” error message while running Python scripts, use the steps below to add Python to PATH on your Mac.