What is a Python virtual environment?

A Python virtual environment (venv) is simply a directory with a particular file structure. It has a Scrips subdirectory that includes links to a Python interpreter as well as subdirectories that hold packages installed in the specific venv.

Links

Virtual Environments and Packages (Python Docs)

Create and Use Virtual Environments

How to launch python Idle from a virtual environment (virtualenv)

Steps (Windows 10)

The following are executed in a single command window.

"my-venv-projects" and "project-venv" are place holders. Create your own directories.

1. Create a directory to hold one or more VENV projects
   
   mkdir c:\Users\my-venv-projects dir c:\Users\my-venv-projects


2. Create a directory for a project's VENV
   
   cd c:\Users\my-venv-projects python -m venv project-venv dir


3. Go to the project's VENV directory
   
   cd project-venv dir


4. Create The Project's VENV
   
   python -m venv project-venv dir


5. Activate the Project's VENV
   
   .\Scripts\activate.bat
   
   Note: The command prompt will change.
   # After activating a VENV you are using # a modified environment. To see the # modified environment's path variable, # Run the following program in an # activated VENV. (try before and after) import sys for p in sys.path: print(p)


6. Install Modules (for example pandas)
   
   python -m pip install pandas ... ... ...
   
   You only need to do this once.
   The modules become part of the VENV.


7. Start The IDLE
   
   python -m idlelib.idle
   
   Do your work in the IDLE.
   The command window will "hang" until the IDLE exits.


8. Deactivate the Project's VENV
   
   .\Scripts\deactivate.bat
   
   Note: The command prompt will change.


9. To delete the project completely, delete the directory project-venv and all of the files under it.
   
   rmdir c:\Users\my-venv-projects\project-venv /s