title: Python variable that updates when another variable updates
body: <p>Let's say I have a text file and its path. I have a variable file_path that points to the file name. I then have this second variable called file_data which is the text of that file path. When I update the file_path, I also have to update file_data separately which is kind of tedious. Is there some code I can attach to allow me to update file_data when I change file_path?</p>