Virtualenv in Python3

A virtual environment is an independent directory tree that accommodates the Python installation for a specific version of Python, along with a certain number of additional packages.

Virtualenv can be defined as a tool that creates isolated Python environments. In the versions of Python 3.3 and above, a subset of it has been coordinated into the standard library, which can be accessed by the venv module.

This tutorial will discuss what a virtual environment is and how to create it in Python 3.

Use the venv Module in Python

In Python 2, the virtualenv module was used for creating and managing virtual environments. It was replaced with the venv module in Python 3.

The venv module offers support for generating lightweight virtual environments along with their site directories, which can be segregated from the system directories if the user wants.

Creating the Virtual Environment

Whenever a user needs to switch projects, they can simply generate a new virtual environment and do not need to worry about the disintegration of the packages installed in the other existing environments. Using a virtual environment for developing Python applications is always recommended.

The creation of a virtual environment can be done by using the following command.

python3 -m venv envname

The second argument in the above code is the location to generate the virtual environment. It can generally be created in the user’s project and can be given a name.

Activating a Virtual Environment

Before reaching the stage where we can install or use packages in the virtual environment, we first need to activate them. When a virtual environment is activated, it puts the virtual pip and python executables into your shell’s path.

.\envname\Scripts\activate

Confirming our existence in the virtual environment can be done by checking the current location of the Python Interpreter.

where python
# Output: .../env/bin/python.exe

The pip and python commands will continue to work as long as the virtual environment is active and the Python application will be able to use and import packages.

Leaving the Virtual Environment

Switching to different projects and environments is possible in this case. Leaving a particular virtual environment for another one is also a possibility.

The following code uses a simple command used to leave the virtual environment.

deactivate

If there is a need to enter this particular virtual environment again, the above instructions can be followed, except we don’t activate the virtual environment. Re-creation of the virtual environment does not need to happen.