In this post, I'll review creating virtual environments on three different operating systems: Windows 10, Linux and Mac OSX. Using virtual environments is good programming practice when using Python. A virtual environment will separate the Python interpreter and installed modules from the main Python installation.
I use three different operating systems on three different computers:
- Work: Windows 10 (no admin access)
- Home Office: Ubuntu 16.04 LTS
- Laptop: Mac OSX
Setting up a Python virtual environment is different on each one of these operating systems. Let's see at what happens when we try and create a new virtual environment in each.
Ubuntu 16.04
Linux should be the easiest to get a new virtualenv up and running. In Ubuntu 16.04, I have a terminal and admin access (can use sudo). But look what happens when I try to set up a new virtualenv without any flags or customization:
$ mkvirtualenv webscrape
$ source activate webscrape
(webscrape)$ which python
$ 2.7.1
The default installation is legacy Python!? I don't want the legacy 2.7 version, I want at least Python 3.2 and would prefer Python 3.6. Let's delete that legacy Python environment. Make sure the virtual environment is deactivated first.
(webscrape)$ source deactivate
$ rmvirtualenv webscrape
Let's try to specify Python 3 with the -p python3 flag
$ mkvirtualenv -p python3 webscrape
$ error
Now what? Path is too long? How is that possible? What happens when we see which Python version is the default python3?
$ which python3
$ bin/usr/anaconda/python3
So that's the flag we need to use when the viruatlenv is created. The --python='which python3' flag will point virtualenvwrapper to the correct Python version. The new virtualenv is initiated with the full file path to our new environment ~/.virtualenvs/webscrape
$ mkvirtualenv --python='which python3' ~/.virtualenvs/webscrape
(webscrape)$ python
Python 3.6.2
Nice. Now we can pip install away. So what about creating a new virtual environment on a MacBook Air with OSX?
Mac OSX
Mac OSX has a terminal too. I get to it by going to the finder and clicking the search in the upper right or using [command] + [space] to bring up the spotlight search bar. Type terminal into the search bar. Setting up a virtualenv should be pretty easy right?
$ mkvirtualenv webscrape
$ source activate webscrape
(webscrape)$ which python
python 2.7
Again!? More legacy Python?! Stop it already with the legacy Python. We want Python! Preferably 3.6. Gotta make sure that Python 3 is installed some where. rmvirtualenv that thing.
(webscrape)$ source deactivate
$ rmvirtualenv webscrape
$ which python3
$ usr/bin/python
$ virtualenv -p python3 webscrape
$ source activate webscrape
(webscrape)$ python
python 3.6.2
OK. Two down and one to go. Is this any easier on Windows 10? Especially with no admin access? Can't be right? Let's see.
Windows 10 (no admin access)
I have a Windows 10 machine at work with no admin access. I can't install any programs on my work computer that use the Windows active directory (which is most programs). The Python distribution that has worked out the best has been Anaconda. Besides coming with Python 3, and having a bunch of packages already installed, it also comes with a command line client call the Anaconda Prompt. The Anaconda Prompt operates a little like the terminal on Linux and Mac OSX, but some of the commands are a little different. To make a new virtual environment from the Anaconda Prompt type:
$ conda create -n webscrape python=3.6
$ proceed ([y]/n)?
$ conda activate webscrape
(webscrape)$ python --version
python 3.6.3 :: Anaconda, Inc.
Rockin' right? Turns out that the Windows 10 virtual environment was one of the easiest to set up. Who would have guessed that? That's one piece of magic from the Anaconda distribution. If you are using Windows, I think Anaconda is the way to go.
End Note:
Maybe it's best to use conda on both OSX and Linux too... You don't have to mess around with ~/.bash_profile or pointing virtualenv wrapper to the proper directory.