Checking for Python Installation on Windows

Checking for Python in the Command Prompt

The first way to check for a Python installation is through the Windows Command Prompt. This is a quick and easy method.

Using python --version

1. Open the Command Prompt: Press the Windows key, type cmd, and press Enter.

2. Type the following command and press Enter:

   python --version

   If Python is installed and configured correctly, this will display the Python version number (e.g., Python 3.11.4).

Using py --version

Sometimes, especially on newer Windows systems, the python command might not work directly. The py launcher is a more reliable way to check.

1. In the same Command Prompt window, type:

   py --version

   This command uses the Python launcher to find and display the default Python version.

Checking for Python in Windows Settings

If the command prompt doesn't show a Python installation, or you want to confirm, you can check in the Windows Settings.

1. Open Settings: Press the Windows key + I.

2. Navigate to "Apps" then "Apps & features".

3. In the list of installed apps, look for "Python".

   • If you find "Python", it's installed. The version number will usually be displayed alongside the name (e.g., "Python 3.9 (64-bit)").
   • You might see multiple entries for Python (e.g., "Python 3.8", "Python 2.7"). This indicates you have multiple versions installed.

Understanding Python 2 and Python 3

If you find both Python 2 and Python 3 installed, it's important to understand the difference.

• Python 2: An older version of Python that is no longer officially supported. New projects should not use Python 2.
• Python 3: The current and actively maintained version of Python. All new development should be done with Python 3.

When using the command prompt, python might default to Python 2 if it's installed. Using py is generally recommended as it allows you to specify which version you want to use. You can also explicitly call Python 3 using python3 --version if it's available.

Important Note: Python 2 reached its end-of-life on January 1, 2020. You should migrate any existing Python 2 code to Python 3.

For more information on the differences between Python 2 and 3, refer to the official Python documentation: https://docs.python.org/3/howto/python2.html

You can also find helpful information about the Python launcher for Windows here: https://docs.python.org/3/using/windows.html#the-py-launcher