[python] IOError: [Errno 13] Permission denied

I had a similar problem. I was attempting to have a file written every time a user visits a website.

The problem ended up being twofold.

1: the permissions were not set correctly

2: I attempted to use
f = open(r"newfile.txt","w+") (Wrong)

After changing the file to 777 (all users can read/write)
chmod 777 /var/www/path/to/file
and changing the path to an absolute path, my problem was solved
f = open(r"/var/www/path/to/file/newfile.txt","w+") (Right)