from pyparsing import * text = """Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum""" # find all words beginning with a vowel vowels = "aeiouAEIOU" initialVowelWord = Word(vowels,alphas) # Unfortunately, searchString will advance character by character through # the input text, so it will detect that the initial "Lorem" is not an # initialVowelWord, but then it will test "orem" and think that it is. So # we need to add a do-nothing term that will match the words that start with # consonants, but we will just throw them away when we match them. The key is # that, in having been matched, the parser will skip over them entirely when # looking for initialVowelWords. consonants = ''.join(c for c in alphas if c not in vowels) initialConsWord = Word(consonants, alphas).suppress() # using scanString to locate where tokens are matched for t,start,end in (initialConsWord|initialVowelWord).scanString(text): if t: print(start,':', t[0]) # add parse action to annotate the parsed tokens with their location in the # input string def addLocnToTokens(s,l,t): t['locn'] = l t['word'] = t[0] initialVowelWord.setParseAction(addLocnToTokens) for ivowelInfo in (initialConsWord | initialVowelWord).searchString(text): if not ivowelInfo: continue print(ivowelInfo.locn, ':', ivowelInfo.word) # alternative - add an Empty that will save the current location def location(name): return Empty().setParseAction(lambda s,l,t: t.__setitem__(name,l)) locateInitialVowels = location("locn") + initialVowelWord("word") # search through the input text for ivowelInfo in (initialConsWord | locateInitialVowels).searchString(text): if not ivowelInfo: continue print(ivowelInfo.locn, ':', ivowelInfo.word)