What is a Virtual Environment in Python?
A virtual environment is a self-contained directory that contains a Python interpreter and a set of libraries installed for a specific project.
Why is a Virtual Environment used in Python ?
Virtual environments enable developers to create isolated environments for different projects, each with their own set of dependencies.
Python has vast library of modules and packages available for developers. Each project you make can have multiple modules and dependencies that you need to install. Managing these dependencies for a multiple number of projects can be challenging, as installing packages globally can lead to version conflicts between projects.
When you activate a virtual environment, any Python package you install or update will be installed only in that environment and won’t interfere with other environments or the global Python installation.
How to create a virtual environment?
In Python , virtual environments are created using the venv module, which is included in the standard library.
To create a virtual environment, you need to open a terminal or command prompt and navigate to the directory where you want to create the environment. Once there, you can create the environment using the following command:
python3 -m venv myenv
or
python -m venv myenv
This command creates a new virtual environment called myenv in the current directory. You can replace myenv with any name you prefer. So if you want to name your virtual environment say `john`, the command would go like this:
python3 -m venv john
How to activate a virtual environment in Python?
To activate the environment in windows you need to run the following command:
.\myvenv\Scripts\activate
Where myenv is the name of your virtual environment. So if the name of your virtual environment was say john, the command would go like this:
.\john\Scripts\activate
To activate the environment in MacOS or Linux you need to run the following command:
source venv/bin/activate
Where venv is the name of your virtual environment.
Your virtual environment should now be activated and you should see the name of the virtual environment in your terminal prompt like this:
Once the environment is activated, you can install packages using pip, just like you would in a global installation.
For example, to install the requests package, you can run the following command:
pip install requests
How to Deactivate a virtual environment?
To deactivate the virtual environment, you can run the following command:
Deactivate
What are the benefits of using virtual environments?
Virtual environments are essential for managing dependencies in Python projects, and they provide several benefits, including:
- Isolation: Each virtual environment is isolated from other environments and the global Python installation. This ensures that packages installed in one environment do not interfere with other environments or the system Python installation.
- Reproducibility: By creating a virtual environment for each project, you can ensure that each project has the same dependencies and versions. This makes it easier to debug issues.
- Security: Virtual environments help to reduce the attack surface by limiting the number of packages installed globally. This helps reduce the risk of security vulnerabilities.
- Flexibility: Virtual environments make it easy to switch between different versions of Python and different versions of packages. This, in turn, enables you to test and develop in different environments without impacting other projects.
Is it absolutely necessary to use virtual environments?
While virtual environments are not strictly necessary, they are highly recommended, especially for projects with dependencies or when working in a team. By using virtual environments, you can avoid dependency conflicts, reproduce environments, manage dependencies, improve security, and increase portability.