title: Python raw strings and trailing backslash
body: <p>I ran across something once upon a time and wondered if it was a Python "bug" or at least a misfeature.  I'm curious if anyone knows of any justifications for this behavior.  I thought of it just now reading "Code Like a Pythonista," which has been enjoyable so far.  I'm only familiar with the 2.x line of Python.</p>
  
  <p>Raw strings are strings that are prefixed with an <code>r</code>.  This is great because I can use backslashes in regular expressions and I don't need to double everything everywhere.  It's also handy for writing throwaway scripts on Windows, so I can use backslashes there also.  (I know I can also use forward slashes, but throwaway scripts often contain content cut&amp;pasted from elsewhere in Windows.)</p>
  
  <p>So great!  Unless, of course, you really want your string to end with a backslash.  There's no way to do that in a 'raw' string.</p>
  
  <pre><code>In [9]: r'\n'
  Out[9]: '\\n'
  
  In [10]: r'abc\n'
  Out[10]: 'abc\\n'
  
  In [11]: r'abc\'
  ------------------------------------------------
     File "&lt;ipython console&gt;", line 1
       r'abc\'
             ^
  SyntaxError: EOL while scanning string literal
  
  
  In [12]: r'abc\\'
  Out[12]: 'abc\\\\'
  </code></pre>
  
  <p>So one backslash before the closing quote is an error, but two backslashes gives you two backslashes!  Certainly I'm not the only one that is bothered by this?</p>
  
  <p>Thoughts on why 'raw' strings are 'raw, except for backslash-quote'?  I mean, if I wanted to embed a single quote in there I'd just use double quotes around the string, and vice versa.  If I wanted both, I'd just triple quote.  If I really wanted three quotes in a row in a raw string, well, I guess I'd have to deal, but is this considered "proper behavior"?</p>
  
  <p>This is particularly problematic with folder names in Windows, where the backslash is the path delimeter.</p>