title: Python os chdir error with folder starting with a number Windows folder
body: <p>Spent 3 hours looking how to use <code>os.chdir</code>, I got an <code>OSError</code> when running this code:</p>
  
  <pre><code>dir1= "D:\_devs\Python01\project\03-Connect_\PyBind"
  
  os.chdir(dir1)
  </code></pre>
  
  <blockquote>
    <p>OSError: [WinError 123] The filename, directory name, or volume label syntax is incorrect: <code>'D:\\_devs\\Python01\\project\x03-Connect_\\PyBind\\examples'</code></p>
  </blockquote>
  
  <p>The definition of <code>dir1</code> cannot be modified (because I want to keep copy/paste from windows folder (ex by using <code>r'&lt;string&gt;</code> or slash)</p>
  
  <p>But the <code>dir1</code> variable can be modified by string manipulation.</p>
  
  <p>Why <code>\x</code>  is generated ? </p>
  
  <p>EDIT2 (leasing space remove):</p>
  
  <pre><code>    dir1 = r"D:\_devs\Python01\project\03-Connect_Java_CPP_Excel\PyBindGen\examples"
  
       dir2= os.path.abspath(dir1)
  
      os.chdir(dir1)
  </code></pre>
  
  <p>still have the error...</p>