title: Python file path failing in pycharm regex confusion
body: <p>I am a relatively new python user and am getting a funky error using my IDE (pycharm), but not when using the cmd line. </p>
  
  <p>Simply I:</p>
  
  <pre><code>path ='C:\Users\Dell\Downloads\users.dat'
  
  import pandas as pd
  unames = ['user_id', 'gender', 'age', 'occupation', 'zip']
  users = pd.read_table(path, sep='::', header=None, names=unames)
  </code></pre>
  
  <p>After which I receive an error that indicates: </p>
  
  <pre><code>ParserWarning: Falling back to the 'python' engine because the 'c' engine does not 
  support regex separators; you can avoid this warning by specifying engine='python'.
  ParserWarning)
  </code></pre>
  
  <p>When i input the identical commands into the cmd line and print <code>users</code> the data prints as expected (i.e., no errors or anything funky).</p>
  
  <p>EDIT: similarly when I input </p>
  
  <pre><code>ratingsdata ='C:\Users\Dell\Downloads\ratings.dat'
  </code></pre>
  
  <p>I get a funky <code>IOError: [Errno 22] invalid mode ('r') or filename:</code> Not sure as to why the <code>/r</code> is not ok in a file path... I understand it's regex, but within the quoted lines??</p>
  
  <p>Help!</p>