Operation Manual

Human-computer interfacing
124
Notes:
When using this program, you will notice that the value of the cookie is remembered
even if you close the web browser.
How does it work? First, we display the current value of the cookie. If the
“cookiechange” variable is set, the value of the cookie is changed and this is sent
back to the web browser to store. The cookie has a maximum age though – we
have used 30 days in this example. The cookie may be lost even sooner if it
is deleted by the user in the web browser. The web browser may even be set up
to ignore cookies completely and never store them, although this is not usually
the case.
Further reading
More information about the “WebOb” library can be found at
http://docs.webob.org/en/latest/
There are also several Python web frameworks available that do a lot of the work
for you. A framework is recommended if you are thinking about writing an entire
website. A popular example is the Django framework; see
http://www.djangoproject.com/
We have only given a very small taster of what is possible here – there is a huge
amount that can be learned about writing web applications.