How to use the tesserocr.iterate_level function in tesserocr

def check_test(): 
    api.SetImageFile(image)
    api.SetVariable("save_blob_choices", "T")
    api.SetRectangle(37, 228, 548, 31)
    api.Recognize()

    ri = api.GetIterator()
    level = RIL.SYMBOL
    for r in iterate_level(ri, level):
        symbol = r.GetUTF8Text(level)  # r == ri
        conf = r.Confidence(level)
        if symbol:
            print("symbol ", symbol, " confidence", conf)
        indent = False
        ci = r.GetChoiceIterator()
        for c in ci:
            if indent:
                print('\t\t '),
            print('\t- '),
            choice = c.GetUTF8Text()  # c == ci
            print(u'{} conf: {}'.format(choice, c.Confidence()))
            indent = True
        print('---------------------------------------------')

def test_result_iterator(self):
        """Test result iterator."""
        self._api.SetImageFile(self._image_file)
        self._api.Recognize()
        it = self._api.GetIterator()
        level = tesserocr.RIL.WORD
        for i, w in enumerate(tesserocr.iterate_level(it, level)):
            text = w.GetUTF8Text(level)
            blanks = w.BlanksBeforeWord()
            if i == 0:
                self.assertEqual(text, "The")
                self.assertEqual(blanks, 0)
            elif i == 1:
                self.assertEqual(text, "(quick)")
                self.assertEqual(blanks, 1)
            else:
                break

def classifier_choices():
    api.SetImageFile('/home/johannes/Repos/tesseract/testing/phototest.tif')
    api.SetVariable("save_blob_choices", "T")
    api.SetRectangle(37, 228, 548, 31)
    api.Recognize()

    ri = api.GetIterator()
    level = RIL.SYMBOL
    # level = RIL.PARA paragraj
    for r in iterate_level(ri, level):
        symbol = r.GetUTF8Text(level)  # r == ri
        conf = r.Confidence(level)
        test = r.SetLineSeparator('\a')
        lang = r.WordRecognitionLanguage()
        if symbol:
            print(u'symbol {}, conf: {}'.format(symbol, conf))
        indent = False
        ci = r.GetChoiceIterator()

        for c in ci:
            if indent:
                print('\t\t ')
            print('\t- ')
            choice = c.GetUTF8Text()  # c == ci
            print(u'{} conf: {}'.format(choice, c.Confidence()))
            indent = True