Introduction
This tutorial will get you up and running with a local Python 3 programming environment in Ubuntu 16.04.
Python is a versatile programming language that can be used for many
different programming projects. First published in 1991 with a name
inspired by the British comedy group Monty Python, the development team
wanted to make Python a language that was fun to use. Easy to set up,
and written in a relatively straightforward style with immediate
feedback on errors, Python is a great choice for beginners and
experienced developers alike. Python 3 is the most current version of
the language and is considered to be the future of Python.
This tutorial will guide you through installing Python 3 on your
local Linux machine and setting up a programming environment via the
command line. This tutorial will explicitly cover the installation
procedures for Ubuntu 16.04, but the general principles apply to any
other distribution of Debian Linux.
Prerequisites
You will need a computer with Ubuntu 16.04 installed, as well as have
administrative access to that machine and an internet connection.
Step 1 — Setting Up Python 3
We’ll be completing our installation and setup on the command line,
which is a non-graphical way to interact with your computer. That is,
instead of clicking on buttons, you’ll be typing in text and receiving
feedback from your computer through text as well. The command line, also
known as a shell, can help you modify and automate many of the tasks
you do on a computer every day, and is an essential tool for software
developers. There are many terminal commands to learn that can enable
you to do more powerful things. The article “
An Introduction to the Linux Terminal” can get you better oriented with the terminal.
On Ubuntu 16.04, you can find the Terminal application by clicking on
the Ubuntu icon in the upper-left hand corner of your screen and typing
“terminal” into the search bar. Click on the Terminal application icon
to open it. Alternatively, you can hit the
CTRL,
ALT, and
T keys on your keyboard at the same time to open the Terminal application automatically.
Ubuntu 16.04 ships with both Python 3 and Python 2 pre-installed. To
make sure that our versions are up-to-date, let’s update and upgrade the
system with
apt-get:
- sudo apt-get update
- sudo apt-get -y upgrade
The
-y flag will confirm that we are agreeing for all
items to be installed, but depending on your version of Linux, you may
need to confirm additional prompts as your system updates and upgrades.
Once the process is complete, we can check the version of Python 3 that is installed in the system by typing:
You will receive output in the terminal window that will let you know
the version number. The version number may vary, but it will look
similar to this:
Output
Python 3.5.2
To manage software packages for Python, let’s install
pip:
- sudo apt-get install -y python3-pip
OR
sudo apt-get install python-pip
A tool for use with Python,
pip installs and manages
programming packages we may want to use in our development projects.
You can install Python packages by typing:
- pip3 install package_name
Here,
package_name can
refer to any Python package or library, such as Django for web
development or NumPy for scientific computing. So if you would like to
install NumPy, you can do so with the command
pip3 install numpy.
There are a few more packages and development tools to install to
ensure that we have a robust set-up for our programming environment:
- sudo apt-get install build-essential libssl-dev libffi-dev python-dev
Once Python is set up, and pip and other tools are installed, we can set up a virtual environment for our development projects.
Step 2 — Setting Up a Virtual Environment
Virtual environments enable you to have an isolated space on your
computer for Python projects, ensuring that each of your projects can
have its own set of dependencies that won’t disrupt any of your other
projects.
Setting up a programming environment provides us with greater control
over our Python projects and over how different versions of packages
are handled. This is especially important when working with third-party
packages.
You can set up as many Python programming environments as you want.
Each environment is basically a directory or folder in your computer
that has a few scripts in it to make it act as an environment.
We need to first install the
venv module, part of the standard Python 3 library, so that we can invoke the
pyvenv command which will create virtual environments for us. Let’s install venv by typing:
- sudo apt-get install -y python3-venv
With this installed, we are ready to create environments. Let’s
choose which directory we would like to put our Python programming
environments in, or we can create a new directory with
mkdir, as in:
- mkdir environments
- cd environments
Once you are in the directory where you would like the environments
to live, you can create an environment by running the following command:
Essentially,
pyvenv sets up a new directory that contains a few items which we can view with the
ls command:
Output
bin include lib lib64 pyvenv.cfg share
Together, these files work to make sure that your projects are
isolated from the broader context of your local machine, so that system
files and project files don’t mix. This is good practice for version
control and to ensure that each of your projects has access to the
particular packages that it needs. Python Wheels, a built-package format
for Python that can speed up your software production by reducing the
number of times you need to compile, will be in the Ubuntu 16.04
share directory.
To use this environment, you need to activate it, which you can do by
typing the following command that calls the activate script:
- source my_env/bin/activate
Your prompt will now be prefixed with the name of your environment, in this case it is called
my_env.
Your prefix may look somewhat different, but the name of your
environment in parentheses should be the first thing you see on your
line:
This prefix lets us know that the environment
my_env
is currently active, meaning that when we create programs here they
will use only this particular environment’s settings and packages.
Note: Within the virtual environment, you can use the command python instead of python3, and pip instead of pip3 if you would prefer. If you use Python 3 on your machine outside of an environment, you will need to use the python3 and pip3 commands exclusively.
After following these steps, your virtual environment is ready to use.
Step 3 — Creating a Simple Program
Now that we have our virtual environment set up, let’s create a
simple “Hello, World!” program. This will make sure that our environment
is working and gives us the opportunity to become more familiar with
Python if we aren’t already.
To do this, we’ll open up a command-line text editor such as nano and create a new file:
Once the text file opens up in the terminal window we’ll type out our program:
print("Hello, World!")
Exit nano by typing the
control and
x keys, and when prompted to save the file press
y.
Once you exit out of nano and return to your shell, let’s run the program:
The hello.py program that you just created should cause your terminal to produce the following output:
Output
Hello, World!
To leave the environment, simply type the command
deactivate and you will return to your original directory.
Conclusion
Congratulations! At this point you have a Python 3 programming
environment set up on your local Ubuntu machine and can begin a coding
project!
To set up Python 3 on another computer, follow the local programming environment guides for
Debian 8,
CentOS 7,
Windows 10, or
macOS.
With your local machine ready for software development, you can continue to learn more about coding in Python by following “
Understanding Data Types in Python 3” and “
How To Use Variables in Python 3”.
Reference Link:
https://www.digitalocean.com/community/tutorials/how-to-install-python-3-and-set-up-a-local-programming-environment-on-ubuntu-16-04
