Configuring Ubuntu for Python Web Development¶
Note: the following instructions assume that you are connected to the Internet and that you have both the
universepackage repositories enabled. All unix shell commands are assumed to be running from your home directory ($HOME). Finally, any command that begins with
sudoassums that you have administrative rights on your machine. If you do not — please ask your system administrator about installing the software you need.
What follows are instructions for setting up an Ubuntu 16.04 (Xenial) home environment for use with this book. I use Ubuntu GNU/Linux for both development and testing of the book, so it is the only system about which I can personally answer setup and configuration questions.
In the spirit of software freedom and open collaboration, please contact me if you would like to maintain a similar appendix for your own favorite system. I’d be more than happy to link to it or put it on the Open Book Project site, provided you agree to answer user feedback concerning it.
Ubuntu 16.04 comes with both Python 2 and Python 3 installed. Typing
python at the shell prompt still launches Python 2. Use the command
python3 for Python 3.
In addition to the debian packages in the Ubuntu Package archive, we will be using Python software from the Python Package Index or PyPI. The tool for installing packages from PyPI is called pip. Since we want Python 3 packages installed which will work with the Python 3 already on our Ubuntu system, we will use the Ubuntu python3-pip debian package.
To add this package run following from the unix command prompt:
$ sudo apt install python3-pip
Now would also be a good time to install a few other packages you will want to have on your system:
$ sudo apt install python3-tk pep8 bzr
$ sudo apt install python3-bottle
>>> import bottle
at the python prompt to varify that it is working.
Vim can be used very effectively for Python
development, but Ubuntu only comes with the
vim-tiny package installed by
default, so it doesn’t support color syntax highlighting or auto-indenting.
To use Vim, do the following:
From the unix command prompt, run:
$ sudo apt install vim
Create a file in your home directory named
.vimrcthat contains the following:
syntax enable filetype indent on set et set sw=4 set smarttab map <f3> :w\|!python3 % <cr> map <f4> :w\|!python3 -m doctest -v % <cr> map <f8> :w\|!pep8 % -v <cr>
When you edit a file with a
.py extension, you should now have color systax
highlighting and auto indenting. Pressing the
<f3> key should run your
program, and bring you back to the editor when the program completes.
<f4> runs the program with the verbose (
-v) switch set, which will be
helpful when running doctests.
<f8> will run the pep8 style checker against
your program source, which is useful in helping you learn to write Python
programs with good styling.
To learn to use vim, run the following command at a unix command prompt:
The following creates a useful environment in your
home directory for using
pip3 to install packages into your home directory and for adding your
own Python libraries and executable scripts:
From the command prompt in your home directory, create
libsubdirectories of your
.localdirectory by running the following command:
$ mkdir .local/lib .local/bin
Now add a
$ mkdir .local/lib/my_python
Add the following lines to the bottom of your
.bashrcin your home directory:
EDITOR=vim PATH=$HOME/.local/bin$PATH PYTHONPATH=$HOME/.local/lib/my_python export EDITOR PATH PYTHONPATH
This will set your prefered editor to Vim, add your own
.local/bindirectory as a place to put executable scripts, and add
.local/lib/my_pythonto your Python search path so modules you put there will be found by Python.
$ . .bashrc
The version here is modified to work with Python 3 on Ubuntu 16.04.
lumpy.py to download the module.
Put this file in your
.local/lib/my_python directory after your
$HOME environment is configured.
Lumpy is used in several of the exercises in this book to help illustrate python data structures.
Making a python script executable and runnable from anywhere¶
On unix systems, Python scripts can be made executable using the following process:
Add this line as the first line in the script:
At the unix command prompt, type the following to make
$ chmod +x myscript.py
.local/bindirectory, and it will be runnable from anywhere.