title: Remove all characters before comma of every line in a file in python
body: <p>I need a small function in python that would read in a file and then remove all the characters up to AND INCLUDING a comma character. so for instance the following two line file:</p>
  
  <pre><code>hello,my name is
  john,john, mary
  </code></pre>
  
  <p>would be:</p>
  
  <pre><code>my name is
  john, mary
  </code></pre>