You use PythonAnywhere to do the exercises for this course. Follow their instructions to create a free/beginner account. You should not need anything beyond the free account for this account.
You can view a video walkthrough of this handout.
Once you have created your PythonAnywhere account and logged in go to "Consoles" and create a new Bash console - or simply go back into one of your consoles if you have one running. Free accounts only get two consoles so you do want to reuse them whenever you can.
You are using the Linux Bash command line. It is like Windows Command Prompt or Apple Terminal program. Many of the demonstrations in this course are done using the Apple Terminal program and the exact same commands will work in the Linux shell.
At the '$' prompt you can type some Linux commands:
You can also edit files and make folders using the "Files" feature in the PythonAnywhere user interface.
The PostgreSQL client software (psql) is already installed on PythonAnywhere (thanks!) so no installation
step is needed. You can just run the commands directly. When you go into an assignment on this site it gives
you your connection details and even the
psql command to run:
Password: (hide/show copy)
psql -h pg.pg4e.com -p 5432 -U pg4e_8aaa5842b6 pg4e_8aaa5842b6
You can copy the
psql command into the shell and run it. You will then be prompted for a password
which you can copy into the clipboard without showing it in the assignment and then pasting it into
the PythonAnywhere shell when
psql asks for your password.
Once you enter your password, you can run
psql commands and SQL commands.
In this example, we type several commands:
You will learn many SQL and
psql commands throughout the rest of this course.
There are three ways to edit files in your PythonAnywhere environment, ranging from the easiest to the coolest. You only have to edit the file one of these ways.
(1) Go to the main PythonAnywhere dashboard, browse files, navigate to the correct folder and edit your file.
(2) Or in the command line:
Save the File by pressing 'CTRL-X', 'Y', and Enter
(3) Don't try this most difficult and most cool way to edit files on Linux without a helper
if it is your first time with the
vi text editor.
The vi (or vim) editor is a very powerful text editor that is very well liked by a large fraction (but by no means all) software developers. You can take a look a the "How to Use Vim - Tutorial" from Free Code Camp.
Vi starts in command mode where you can move around the document using the cursor keys. To edit the
file you can and press the
i key to go into 'INSERT' mode, then type your new text and press the
esc key when you are
done. To save the file in command mode, you type
:wq followed by
enter. If you get lost press
enter to get out of the file without saving.
If you aleady know some other command line text editor in Linux, you can use it to edit files. In general, you will find that it often quicker and easier to make small edits to files in the command line rather than a full screen UI. And once you start deploying real applications in production environments like Google, Amazon, Microsoft, etc.. all you will have is command line.