How to use the tesserocr.PSM.SINGLE_WORD function in tesserocr

def test_page_seg_mode(self):
        """Test SetPageSegMode and GetPageSegMode."""
        self._api.SetPageSegMode(tesserocr.PSM.SINGLE_WORD)
        self.assertEqual(self._api.GetPageSegMode(), tesserocr.PSM.SINGLE_WORD)
        self._api.SetPageSegMode(tesserocr.PSM.AUTO)
        self.assertEqual(self._api.GetPageSegMode(), tesserocr.PSM.AUTO)

def test_page_seg_mode(self):
        """Test SetPageSegMode and GetPageSegMode."""
        self._api.SetPageSegMode(tesserocr.PSM.SINGLE_WORD)
        self.assertEqual(self._api.GetPageSegMode(), tesserocr.PSM.SINGLE_WORD)
        self._api.SetPageSegMode(tesserocr.PSM.AUTO)
        self.assertEqual(self._api.GetPageSegMode(), tesserocr.PSM.AUTO)

def _process_existing_words(self, tessapi, words, line_image, line_xywh):
        for word in words:
            word_image, word_xywh = self.workspace.image_from_segment(
                word, line_image, line_xywh)
            if self.parameter['padding']:
                bg = tuple(ImageStat.Stat(word_image).median)
                pad = self.parameter['padding']
                padded = Image.new(word_image.mode,
                                   (word_image.width + 2 * pad,
                                    word_image.height + 2 * pad), bg)
                padded.paste(word_image, (pad, pad))
                tessapi.SetImage(padded)
            else:
                tessapi.SetImage(word_image)
            tessapi.SetPageSegMode(PSM.SINGLE_WORD)
            if self.parameter['textequiv_level'] == 'word':
                LOG.debug("Recognizing text in word '%s'", word.id)
                word_text = tessapi.GetUTF8Text().rstrip("\n\f")
                word_conf = tessapi.AllWordConfidences()
                word_conf = word_conf[0]/100.0 if word_conf else 0.0
                if word.get_TextEquiv():
                    LOG.warning("Word '%s' already contained text results", word.id)
                    word.set_TextEquiv([])
                # todo: consider WordFontAttributes (TextStyle) etc (if not word.get_TextStyle())
                word.add_TextEquiv(TextEquivType(Unicode=word_text, conf=word_conf))
                continue # next word (to avoid indentation below)
            ## glyph level:
            glyphs = word.get_Glyph()
            if glyphs:
                ## external glyph layout:
                LOG.warning("Word '%s' contains glyphs already, recognition might be suboptimal", word.id)