Running Python Scripts

Last updated on 2025-08-13 | Edit this page

Overview

Questions

  • What is a Python script?
  • How can I run a Python script?

Objectives

  • Learn about Python scripts and how to run them.
  • Add dependencies to a Python script.

What is a Python script?


A Python script is just a Python file like example.py. A Python file is also referred to as a module in the context of a Python package but for this lesson we will use the script definition.

Running a script with uv


Below is the contents of a Python script named example.py. This script does not have any external dependencies. It only uses features available in the Python standard library.

PYTHON

# example.py

import random


def main():
    print("Script using standard Python")
    print("Random number is", random.random())


if __name__ == "__main__":
    main()

Use the following command to run the script with uv:

BASH

uv run example.py

Running a script with dependencies


Below is the contents of another Python script named example2.py. This script imports the NumPy package which is an external dependency (not included in Python).

PYTHON

# example2.py

import numpy as np


def main():
    print("Hello from NumPy!")

    a = np.array([1, 2, 3, 4, 5])
    print("a is", a)


if __name__ == "__main__":
    main()

To run this code, uv must install the NumPy package so it can be imported by the script. The command shown below will add a script section that provides the Python version and list of dependencies.

BASH

uv add numpy --script example2.py

PYTHON

# /// script
# requires-python = ">=3.13"
# dependencies = [
#     "numpy",
# ]
# ///

import numpy as np


def main():
    print("Hello from NumPy!")

    a = np.array([1, 2, 3, 4, 5])
    print("a is", a)


if __name__ == "__main__":
    main()

Now you can execute the script using the same run command used in the previous example:

BASH

uv run example2.py

By including the script section in a Python script, anyone can run that Python file with uv. You don’t have to worry about installing Python or creating a virtual environment and downloading dependencies. You just use uv to run the file and it will automatically install Python if it isn’t available on your computer and it will automatically install any dependencies needed to run the script.

Here is a demo of using uv to run a Python script that imports the NumPy package. This recording is animated text (not video); consequently, the text for each command is selectable and can be copied and pasted into your own terminal.

Key Points
  • A Python script is just a single Python file.
  • Dependencies can be added to a script to make it self contained.
  • Scripts can easily be run with uv which handles Python and installation and dependency management.