code: def list_local(paths, prefix=None):
      
      results = []
      for path in paths:
          if os.path.isdir(path):
              for filename in os.listdir(path):
                  fullpath = os.path.join(path, filename)
                  if os.path.isdir(fullpath):
                      results += list_local([fullpath], prefix)
                  else:
                      fullname = fullpath
                      if prefix and fullname.startswith(prefix):
                          fullname = fullname[len(prefix):]
                      mtime = datetime.datetime.fromtimestamp(
                          os.path.getmtime(fullpath), tz=utc)
                      results += [{"Key": fullname,
                          "LastModified": mtime.strftime(
                                  '%a, %d %b %Y %H:%M:%S %Z')}]
          else:
              fullpath = path
              fullname = fullpath
              if prefix and fullname.startswith(prefix):
                  fullname = fullname[len(prefix):]
              mtime = datetime.datetime.fromtimestamp(
                  os.path.getmtime(fullpath), tz=utc)
              results += [{"Key": fullname,
                  "LastModified": mtime.strftime(
                          '%a, %d %b %Y %H:%M:%S %Z')}]
      return results
docs: Returns a list of all files (recursively) present in a directory
      with their timestamp.
  
      Example:
      [{ "Key": "abc.txt",
         "LastModified": "Mon, 05 Jan 2015 12:00:00 UTC"},
       { "Key": "def.txt",
         "LastModified": "Mon, 05 Jan 2015 12:00:001 UTC"},
      ]