code: def get_data_path(self, filename, env_prefix=None):
          
          if env_prefix == None:
              target_file = filename
          else:
              target_file = os.path.join(env_prefix, filename)
  
          if os.path.exists(os.path.join(self._data_path, target_file)):
              return os.path.join(self._data_path, target_file)
          else:
              raise DataNotFoundError(
                  u("Cannot find data file: {0}").format(target_file))
docs: Get data path.
  
          Args:
              filename (string) : Name of file inside of /data folder to retrieve.
  
          Kwargs:
              env_prefix (string) : Name of subfolder, ex: 'qa' will find files in /data/qa
  
          Returns:
              String - path to file.
  
          Usage::
  
              open(WTF_DATA_MANAGER.get_data_path('testdata.csv')
  
          Note: WTF_DATA_MANAGER is a provided global instance of DataManager