Attention: Google Chrome request firing twice when url entered manually

I was writing a simple Django view. That view collected data from user request. During the testing I found a problem: data was collecting twice.

I tested my view by copy-pasting url to address bar of Google Chrome. And before I hit “Enter” request apeared in server log.

I have also tested in Firefox and Opera - extra requests did not appear.

The best solution is to avoid changing application state in GET requests. More info at StackExchange