Refreshing website not changed after modification in Django

I am new to Django. Recently I am doing a project from my peer. It's a small web interface in Django. I made some changes to the source code and I am sure I made it in the right way. The weird thing is that when I refresh the page, nothing changed. However, after few hours or a whole day, the changes displayed, and sometimes the changes disappear again. For example, there is the drop-down menu in the index page, and code controlling this drop-down menu is PROPERTY_TYPE_CHOICE = [['1','Transducer'],['2','Trajectory'], ['3', 'Error_Detecting'], ['4', 'Error_Correcting']].

Then I made some changes to PROPERTY_TYPE_CHOICE = [ ['1', 'Error_Detecting'], ['1', 'Error_Correcting']].

Aft开发者_StackOverflow社区er that when I refresh the website, nothing changed and the first two choices are still there. Some one can explain that to me? Is it the matter of configuration of IE or Firefox?

No. You just need to restart Apache after you make the changes.