title: python os.walk displays mixed windows and unix paths
body: <p>I am trying to identify all files with certain names in a folder. I am using standard code to do that looking like this:</p>
  
  <pre><code>for paths, subdirs, files in os.walk(start_dir, topdown=True):
      for file in files:
          print(os.path.join(paths, file))
  </code></pre>
  
  <p>My problem is about the output of this code in windows machine, basically dynamic parts of the path have wrong slash sign:</p>
  
  <pre><code>D:/JAJA/Projects/DAF/AIM/WEBAPP/trunk/src/main/java/ie/gov/agriculture/aim\aes\AesSheetNumberEntity.java
  D:/JAJA/Projects/DAF/AIM/WEBAPP/trunk/src/main/java/ie/gov/agriculture/aim\aes\DocumentReceivedDetailEntity.java
  D:/JAJA/Projects/DAF/AIM/WEBAPP/trunk/src/main/java/ie/gov/agriculture/aim\aes\DocumentReceivedEntity.java
  D:/JAJA/Projects/DAF/AIM/WEBAPP/trunk/src/main/java/ie/gov/agriculture/aim\aes\DocumentTypeEntity.java
  </code></pre>
  
  <p>start folder which was given is:</p>
  
  <pre><code>D:/JAJA/Projects/DAF/AIM/WEBAPP/trunk/src/main/java/ie/gov/agriculture/aim
  </code></pre>
  
  <p>and the folder separator is unix one: <code>"/"</code></p>
  
  <p>while all subsequent subfolders found by os.walk function have windows slash instead: <code>"\"</code></p>
  
  <p>So at the end I have invalid path which cannot be used straight away. Is this a bug in python os library or what actually?</p>
  
  <p>Currently I can easily replace wrong separator with the right one but I am wondering if it is the only way?</p>