code: def dirsize_get(l_filesWithoutPath, **kwargs):
          
  
          str_path    = ""
          for k,v in kwargs.items():
              if k == 'path': str_path = v
  
          d_ret   = {}
          l_size  = []
          size    = 0
          for f in l_filesWithoutPath:
              str_f   = '%s/%s' % (str_path, f)
              if not os.path.islink(str_f):
                  try:
                      size += os.path.getsize(str_f)
                  except:
                      pass
          str_size    = pftree.sizeof_fmt(size)
  
          return {
              'status':           True,
              'diskUsage_raw':    size,
              'diskUsage_human':  str_size
          }
docs: Sample callback that determines a directory size.