support prompt ner

修改preprocessor增加对prompt模型的支持。
        Link: https://code.alibaba-inc.com/Ali-MaaS/MaaS-lib/codereview/10972542

modelscope/preprocessors/nlp/token_classification_preprocessor.py

@@ -238,7 +238,16 @@ class TokenClassificationTransformersPreprocessor(
         is_split_into_words = self.nlp_tokenizer.get_tokenizer_kwarg(
             'is_split_into_words', False)
         if is_split_into_words:
-            tokens = list(tokens)
+            # for supporting prompt seperator, should split twice. [SEP] for default.
+            sep_idx = tokens.find('[SEP]')
+            if sep_idx == -1 or self.is_lstm_model:
+                tokens = list(tokens)
+            else:
+                tmp_tokens = []
+                tmp_tokens.extend(list(tokens[:sep_idx]))
+                tmp_tokens.append('[SEP]')
+                tmp_tokens.extend(list(tokens[sep_idx + 5:]))
+                tokens = tmp_tokens
 
         if is_split_into_words and self.mode == ModeKeys.INFERENCE:
             encodings, word_ids = self._tokenize_text_by_words(
@@ -250,6 +259,16 @@ class TokenClassificationTransformersPreprocessor(
             encodings, word_ids = self._tokenize_text_with_slow_tokenizer(
                 tokens, **kwargs)
 
+        # modify label mask, mask all prompt tokens (tokens after sep token)
+        sep_idx = -1
+        for idx, token_id in enumerate(encodings['input_ids']):
+            if token_id == self.nlp_tokenizer.tokenizer.sep_token_id:
+                sep_idx = idx
+                break
+        if sep_idx != -1:
+            for i in range(sep_idx, len(encodings['label_mask'])):
+                encodings['label_mask'][i] = False
+
         if self.mode == ModeKeys.INFERENCE:
             for key in encodings.keys():
                 encodings[key] = torch.tensor(encodings[key]).unsqueeze(0)

tests/pipelines/test_named_entity_recognition.py

@@ -262,7 +262,7 @@ class NamedEntityRecognitionTest(unittest.TestCase, DemoCompatibilityCheck):
         self.lcrf_model_id = 'damo/nlp_lstm_named-entity-recognition_chinese-news'
         self.addr_model_id = 'damo/nlp_structbert_address-parsing_chinese_base'
         self.lstm_model_id = 'damo/nlp_lstm_named-entity-recognition_chinese-generic'
-        self.sentence = '这与温岭市新河镇的一个神秘的传说有关。'
+        self.sentence = '这与温岭市新河镇的一个神秘的传说有关。[SEP]地名'
         self.sentence_en = 'pizza shovel'
         self.sentence_zh = '他 继 续 与 貝 塞 斯 達 遊 戲 工 作 室 在 接 下 来 辐 射 4 游 戏 。'
         self.addr = '浙江省杭州市余杭区文一西路969号亲橙里'