使用scanString

Question

我正在尝试使用pyparsing扫描文件。在pyparsing中有一个名为scanString的方法，它确实存在;

   >>> name = pp.Word(pp.alphas)
   >>> text = "**** Farcical aquatic  ceremony"
   >>> for result, start, end in name.scanString(text):
   ...     print "Found {0} at [{1}:{2}]".format(result, start, end)
   ... 
   Found ['Farcical'] at [5:13]
   Found ['aquatic'] at [14:21]
   Found ['ceremony'] at [23:31]

但是我想用句子中的单词扫描一个txt文件。上面的scanString扫描单词中的单词。有没有办法扫描文件？或者，scanString只能像上面一样工作吗？