Managing dependencies for different projects can be challenging. For instance:

• Project A might need an older version of a library (like boto3).
• Project B might need the latest version of the same library.

Installing libraries globally can lead to version conflicts, often called "dependency hell," where updating a library for one project breaks another.

Virtual environments solve this by creating isolated directories for each project. Each environment contains:

• A specific Python interpreter.
• Its own set of installed packages (site-packages).

This ensures that project dependencies are kept separate and self-contained.

Python 3 includes a built-in module, venv, which is the standard way to create virtual environments.

1. Navigate to your project's root directory in your terminal.
2. Run the command:

   python3 -m venv .venv

   • python3 -m venv: Executes the venv module.
   • .venv: The conventional name for the directory containing the virtual environment files. This directory will hold a copy/link of the Python interpreter and associated package directories.

Creating the environment isn't enough; you must activate it for your current shell session. Activation modifies your shell's PATH environment variable, ensuring that the python and pip commands prioritize the versions inside the .venv directory.

• How to Activate: Use the activation script located within the environment's directory (e.g., inside .venv/bin/ or .venv/Scripts/, depending on the OS where it was created). The exact command depends on your shell.
• Indication: Once activated, your shell prompt typically changes to show the name of the active environment (e.g., (.venv)).

With the environment active, use pip to install packages. They will be installed only within the active virtual environment:

pip install <package_name>
# Example: pip install boto3

To exit the virtual environment and return to your global Python context, simply run:

deactivate

The indicator (e.g., (.venv)) will disappear from your prompt.

Using venv means packages are installed within your project's .venv directory, which is owned by your user. This eliminates the need and the risks associated with using sudo pip install. Always install project dependencies into an activated virtual environment using pip install <package>.