This article uses Python version 2.7. If you want to set up virtualenv using Python 3, view the following article instead:
Virtualenv is a tool used to create an isolated Python environment. This environment has its own installation directories that doesn't share libraries with other virtualenv environments (and optionally doesn't access the globally installed libraries either).
Virtualenv is the easiest and recommended way to configure a custom Python environment.
Virtualenv is not installed by default on DreamHost servers. To install, you must first install a custom version of Python.
When you install a custom version, pip is also installed with it. You can then use pip to install virtualenv as shown below.
[server]$ pip install virtualenv
[server]$ pip3 install virtualenv
Creating a virtual environment using a custom Python version
When working with virtual environments in Python, it's common to use a custom version of Python rather than the server's version. View the following article to install any version of Python you like.
To create a new virtual environment using this custom Python version, follow these steps:
- Make a note of the full file path to the custom version of Python you just installed. If you've followed the instructions in the installation article, the full path is:
- Navigate to your site's directory. This is where you'll create the new virtual environment:
[server]$ cd $HOME/example.com
- Create the virtual environment at the same time you specify the version of Python you wish to use. Make sure to change 'username' to your Shell username. In this example, the project is titled 'venv', but you can name this anything you like.
Make sure you specify the path to your custom installation of Python 2. If you do not, you'll end up using the system version of Python.
[server]$ virtualenv -p /home/username/opt/python-2.7.15/bin/python venv
- This creates a local copy of your environment specific to this website. While working on this website, you should activate the local environment in order to make sure you're working with the right versions of your tools and packages.
- Run the following to activate this new virtual environment:
[server]$ source venv/bin/activate
- Finally, check the version of Python being used:
(venv) [server]$ python -V Python 2.7.15
From now on, any package that you install using pip is placed in the virtual environments project folder, isolated from the global Python installation.
It's a good idea to upgrade the version of pip to ensure you can install current modules.
(venv) [server]$ python -m pip install --upgrade pip
You can then check the version.
(venv) [server]$ pip --version
Deactivating your virtualenv
If you are finished working in the virtual environment for the moment, you can deactivate it by running the following:
(venv) [server]$ deactivate
- This puts you back into your Shell user's default settings.
Deleting your virtual environment
To delete a virtual environment, just delete project folder. In this case, it would be:
[server]$ rm -rf venv
Installing custom modules
View the following article for information on how to use pip to install Python modules.