Python PY files does not reflect changes

Python PY files does not reflect changes

I have experience with PHP but now have to manage a python application. It
is already developed and running on live server. On live server we have
beta.domain.com as well. which has its own copy of same source, other than
the main domain application.
Now, when we print something within template it effects but before that,
following MVC, if we try to print or use sys.exit() in "manage.py" or
later imported "settings.py" or then "views.py", nothing effects these
files at all. After any change in just mentioned files, Website still
renders everything and display related template.
Another thing that if even we remove "return
render_to_response('home.html', RequestContext(request, context))" inside
the "views.py" for testing, nothing effects and website still gets
rendered with template.
Do I need to think that if website code is already hosted then in order to
have changes to reflect new one in the code in any file (.py), needs to be
reinitialized by executing any project related file?
I am not sure how python code needs to be updated at all, any quick help
is much appreciated.