title: How to change file names using regular expressions in Python?
body: <p>I have a directory which contains subdirectories which contain files. All the file names have a prefix which I want to eliminate. The prefix is not exactly the same among all the files, but I have a regular expression that represents exactly the language of these prefixes. I'm trying to write a script in Python to change the name of each file to its name without the prefix. I don't know yet how to "play" with files in Python (know just basic i/o operations). Could you help a little?</p>
  
  <p>I use Python 3.</p>