Virtualenv in macOs/ windows in easy way
Virtualenv is a tool that lets you create an isolated Python environment for your project.
A virtual environment allows you to have a virtual installation of Python and packages on your computer.Packages change and get updated often!
It creates an environment that has its own installation directories, that doesn’t share dependencies with other
virtualenv environments (and optionally doesn’t access the globally installed dependencies either). You can even configure what version of Python you want to use for each individual environment. It's very much recommended to use virtualenv when dealing with Python applications.Installation
To install
virtualenv run:$ pip install virtualenv
Usage
If you have a project in a directory called project you can set up
virtualenv for that project by running:$ cd project/
$ virtualenv venv
If you want your
virtualenv to also inherit globally installed packages run:$ virtualenv venv --system-site-packages
These commands create a
venv/ directory in your project where all dependencies are installed. You need to activate it first though (in every terminal instance where you are working on your project):$ source venv/bin/activate
You should see a
(venv) appear at the beginning of your terminal prompt indicating that you are working inside the virtualenv. Now when you install something like this:$ pip install <package>
It will get installed in the
venv/ folder, and not conflict with other projects.
To leave the virtual environment run:
$ deactivate
It is preferable to install big packages (like Numpy), or packages you always use (like IPython) globally. All the rest can be installed in a
virtualenv.Virtualenvwrapper
To make it easier to work on multiple projects that has separate environments you can install
virtualenvwrapper. It's an extension to virtualenv and makes it easier to create and delete virtual environments without creating dependency conflicts.
To install
virtualenvwrapper run:$ pip install virtualenvwrapper
Depending on your setup you might need to install it using
sudo.
Note:
virtualenvwrapper keeps all the virtual environments in ~/.virtualenv while virtualenv keeps them in the project directory.
