How to Use the Command `virtualenvwrapper` (with Examples)

Virtualenvwrapper is a powerful suite of extensions that sit on top of Python’s virtualenv tool, designed to manage multiple virtual environments more efficiently. It provides commands to create, activate, deactivate, and delete virtual environments along with a host of other functionalities that streamline workflow management for Python developers. The tool centralizes all virtual environments in a predefined directory, aiding easy navigation and management of various projects.

Create a New Python Virtual Environment in $WORKON_HOME

Code:

mkvirtualenv virtualenv_name

Motivation:

Creating an isolated Python environment for each project ensures that dependencies for one project do not interfere with those of another. This encapsulation maintains clean and manageable project settings, aiding in consistent development and deployment.

Explanation:

• mkvirtualenv: This command initializes a new virtual environment. It automatically handles the setup, avoiding the need for manually specifying directories or Python resources.
• virtualenv_name: Refers to the desired name of the virtual environment. It’s how you will reference this specific environment in future commands.

Example Output:

Using base prefix '/usr/local'
New python executable in /home/user/.virtualenvs/virtualenv_name/bin/python
Installing setuptools, pip, wheel...
done.

Create a Virtual Environment for a Specific Python Version

Code:

mkvirtualenv --python /usr/local/bin/python3.8 virtualenv_name

Motivation:

Utilizing a specific version of Python for a project can be crucial, especially when dealing with dependencies or libraries that require certain features or modules present only in certain Python versions.

Explanation:

• --python /usr/local/bin/python3.8: This option specifies which Python interpreter to use when creating the environment. By providing the path to python3.8, you’re ensuring that version is used exclusively for this virtual environment.
• virtualenv_name: The intended name for the created environment.

Example Output:

Using base prefix '/usr/local/bin/python3.8'
New python executable in /home/user/.virtualenvs/virtualenv_name/bin/python3.8
Also creating executable in /home/user/.virtualenvs/virtualenv_name/bin/python
Installing setuptools, pip, wheel...
done.

Activate or Use a Different Virtual Environment

Code:

workon virtualenv_name

Motivation:

Switching between projects or tasks frequently requires altering the active environment. This command allows easy activation of the required environment, ensuring you have the correct dependencies loaded.

Explanation:

• workon: A convenient command from virtualenvwrapper that lists available environments and allows activation of the specified one.
• virtualenv_name: Specifies which environment to activate. This must match an existing environment’s name as listed by virtualenvwrapper.

Example Output:

(virtualenv_name) user@host:~$

Stop the Virtual Environment

Code:

deactivate

Motivation:

Once you’ve finished working within a specific virtual environment, deactivating it helps prevent accidental changes or command executions that might affect it. It’s a best practice for managing development tasks separately.

Explanation:

• deactivate: This command exits the current virtual environment and returns the user to the system’s default Python interpreter and environment settings.

Example Output:

user@host:~$

List All Virtual Environments

Code:

lsvirtualenv

Motivation:

With multiple projects, there is a need to quickly survey all virtual environments established on a system. This command provides a straightforward way to list all available environments along with their directory paths.

Explanation:

• lsvirtualenv: Lists all the virtual environments currently created within the $WORKON_HOME directory, providing an overview and easy access to manage them.

Example Output:

virtualenv_name1
virtualenv_name2
...

Remove a Virtual Environment

Code:

rmvirtualenv virtualenv_name

Motivation:

Sometimes, projects become obsolete, or testing environments need to be cleared out. Deleting unused environments saves space and reduces clutter, simplifying project organization.

Explanation:

• rmvirtualenv: Deletes a virtual environment along with all its dependencies and settings.
• virtualenv_name: The name of the environment to be removed.

Example Output:

Removing virtualenv: virtualenv_name...
done.

Get Summary of All Virtualenvwrapper Commands

Code:

virtualenvwrapper

Motivation:

For new users or when encountering unfamiliar scenarios, reviewing a summary of available commands helps in understanding the capabilities of virtualenvwrapper, facilitating efficient problem-solving or exploration of additional features.

Explanation:

• virtualenvwrapper: Displays a list of available commands and options, acting as a quick reference guide.

Example Output:

virtualenvwrapper commands available:
   - mkvirtualenv 
   - rmvirtualenv
   - workon 
   - deactivate
   - lsvirtualenv 
...

Conclusion:

Virtualenvwrapper significantly enhances the management of Python environments by providing user-friendly commands that cover the complete lifecycle of application development and deployment. It helps in maintaining neat, isolated, and manageable Python setups ideal for developers who need to juggle various projects seamlessly.