title: Extract all files with directory path in given directory
body: <p>I have a tar archive in which I have a directory which I need to extract in a given directory.
  For example: I have a directory </p>
  
  <blockquote>
    <p>TarPrefix/x/y/z</p>
  </blockquote>
  
  <p>in a tar archive I want to extract it in a given target directory for example: extracted/a/ this directory should contain all the files and directories contained in directory TarPrefix/x/y/z.</p>
  
  <pre><code>subdir_and_files = [  tarinfo for tarinfo in tar.getmembers()
                        if tarinfo.name.startswith("subfolder/")
                     ]
  </code></pre>
  
  <p>to get the list of all the members in the directory path "subfolder/" and then I extract it using <code>tar.extractall(extracted/a,subdir_and_files)</code>
  but it extracts all the members with their directory path For example this results in  extracted/a/x/y/z.
  Could you please help me in extracting these files in the given folder.</p>