标题增强 (#631)

* Add files via upload

* Update local_doc_qa.py

* Update model_config.py

* Update zh_title_enhance.py

* Add files via upload

* Update README.md

* fix bugs in MyFAISS.delete_doc

* fix:前端知识库获取失败.

* update zh_title_enhance.py

* update zh_title_enhance.py

* Update zh_title_enhance.py

* add test/textsplitter

* add test_zh_title_enhance.py

---------

Co-authored-by: imClumsyPanda <littlepanda0716@gmail.com>
Co-authored-by: JZF <jiangzhifeng_jzf@163.com>
Co-authored-by: fxjhello <127916299+fxjhello@users.noreply.github.com>

chains/local_doc_qa.py

@@ -17,6 +17,7 @@ import models.shared as shared
 from agent import bing_search
 from langchain.docstore.document import Document
 from functools import lru_cache
+from textsplitter.zh_title_enhance import zh_title_enhance
 
 
 # patch HuggingFaceEmbeddings to make it hashable
@@ -56,7 +57,7 @@ def tree(filepath, ignore_dir_names=None, ignore_file_names=None):
     return ret_list, [os.path.basename(p) for p in ret_list]
 
 
-def load_file(filepath, sentence_size=SENTENCE_SIZE):
+def load_file(filepath, sentence_size=SENTENCE_SIZE, using_zh_title_enhance=ZH_TITLE_ENHANCE):
     if filepath.lower().endswith(".md"):
         loader = UnstructuredFileLoader(filepath, mode="elements")
         docs = loader.load()
@@ -79,6 +80,8 @@ def load_file(filepath, sentence_size=SENTENCE_SIZE):
         loader = UnstructuredFileLoader(filepath, mode="elements")
         textsplitter = ChineseTextSplitter(pdf=False, sentence_size=sentence_size)
         docs = loader.load_and_split(text_splitter=textsplitter)
+    if using_zh_title_enhance:
+        docs = zh_title_enhance(docs)
     write_check_file(filepath, docs)
     return docs
 

configs/model_config.py

@@ -173,4 +173,9 @@ BING_SEARCH_URL = "https://api.bing.microsoft.com/v7.0/search"
 
 # 此外，如果是在服务器上，报Failed to establish a new connection: [Errno 110] Connection timed out
 # 是因为服务器加了防火墙，需要联系管理员加白名单，如果公司的服务器的话，就别想了GG
-BING_SUBSCRIPTION_KEY = ""
\ No newline at end of file
+BING_SUBSCRIPTION_KEY = ""
+
+# 是否开启中文标题加强，以及标题增强的相关配置
+# 通过增加标题判断，判断哪些文本为标题，并在metadata中进行标记；
+# 然后将文本与往上一级的标题进行拼合，实现文本信息的增强。
+ZH_TITLE_ENHANCE = True

test/textsplitter/test_zh_title_enhance.py

+from configs.model_config import *
+from langchain.embeddings.huggingface import HuggingFaceEmbeddings
+import nltk
+from vectorstores import MyFAISS
+from chains.local_doc_qa import load_file
+
+
+nltk.data.path = [NLTK_DATA_PATH] + nltk.data.path
+
+if __name__ == "__main__":
+    filepath = os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(__file__))),
+                            "knowledge_base", "samples", "content", "test.txt")
+    embeddings = HuggingFaceEmbeddings(model_name=embedding_model_dict[EMBEDDING_MODEL],
+                                       model_kwargs={'device': EMBEDDING_DEVICE})
+
+    docs = load_file(filepath, using_zh_title_enhance=True)
+    vector_store = MyFAISS.from_documents(docs, embeddings)
+    query = "指令提示技术有什么示例"
+    search_result = vector_store.similarity_search(query)
+    print(search_result)
+    pass

textsplitter/__init__.py

 from .chinese_text_splitter import ChineseTextSplitter
-from .ali_text_splitter import AliTextSplitter
\ No newline at end of file
+from .ali_text_splitter import AliTextSplitter
+from .zh_title_enhance import zh_title_enhance
\ No newline at end of file

textsplitter/zh_title_enhance.py

+from langchain.docstore.document import Document
+import re
+
+
+def under_non_alpha_ratio(text: str, threshold: float = 0.5):
+    """Checks if the proportion of non-alpha characters in the text snippet exceeds a given
+    threshold. This helps prevent text like "-----------BREAK---------" from being tagged
+    as a title or narrative text. The ratio does not count spaces.
+
+    Parameters
+    ----------
+    text
+        The input string to test
+    threshold
+        If the proportion of non-alpha characters exceeds this threshold, the function
+        returns False
+    """
+    if len(text) == 0:
+        return False
+
+    alpha_count = len([char for char in text if char.strip() and char.isalpha()])
+    total_count = len([char for char in text if char.strip()])
+    try:
+        ratio = alpha_count / total_count
+        return ratio < threshold
+    except:
+        return False
+
+
+def is_possible_title(
+        text: str,
+        title_max_word_length: int = 20,
+        non_alpha_threshold: float = 0.5,
+) -> bool:
+    """Checks to see if the text passes all of the checks for a valid title.
+
+    Parameters
+    ----------
+    text
+        The input text to check
+    title_max_word_length
+        The maximum number of words a title can contain
+    non_alpha_threshold
+        The minimum number of alpha characters the text needs to be considered a title
+    """
+
+    # 文本长度为0的话，肯定不是title
+    if len(text) == 0:
+        print("Not a title. Text is empty.")
+        return False
+
+    # 文本中有标点符号，就不是title
+    ENDS_IN_PUNCT_PATTERN = r"[^\w\s]\Z"
+    ENDS_IN_PUNCT_RE = re.compile(ENDS_IN_PUNCT_PATTERN)
+    if ENDS_IN_PUNCT_RE.search(text) is not None:
+        return False
+
+    # 文本长度不能超过设定值，默认20
+    # NOTE(robinson) - splitting on spaces here instead of word tokenizing because it
+    # is less expensive and actual tokenization doesn't add much value for the length check
+    if len(text) > title_max_word_length:
+        return False
+
+    # 文本中数字的占比不能太高，否则不是title
+    if under_non_alpha_ratio(text, threshold=non_alpha_threshold):
+        return False
+
+    # NOTE(robinson) - Prevent flagging salutations like "To My Dearest Friends," as titles
+    if text.endswith((",", ".", "，", "。")):
+        return False
+
+    if text.isnumeric():
+        print(f"Not a title. Text is all numeric:\n\n{text}")  # type: ignore
+        return False
+
+    # 开头的字符内应该有数字，默认5个字符内
+    if len(text) < 5:
+        text_5 = text
+    else:
+        text_5 = text[:5]
+    alpha_in_text_5 = sum(list(map(lambda x: x.isnumeric(), list(text_5))))
+    if not alpha_in_text_5:
+        return False
+
+    return True
+
+
+def zh_title_enhance(docs: Document) -> Document:
+    title = None
+    if len(docs) > 0:
+        for doc in docs:
+            if is_possible_title(doc.page_content):
+                doc.metadata['category'] = 'cn_Title'
+                title = doc.page_content
+            elif title:
+                doc.page_content = f"下文与({title})有关。{doc.page_content}"
+        return docs
+    else:
+        print("文件不存在")

vectorstores/MyFAISS.py

@@ -7,6 +7,7 @@ from langchain.docstore.document import Document
 import numpy as np
 import copy
 import os
+from configs.model_config import *
 
 
 class MyFAISS(FAISS, VectorStore):
@@ -23,6 +24,9 @@ class MyFAISS(FAISS, VectorStore):
                          docstore=docstore,
                          index_to_docstore_id=index_to_docstore_id,
                          normalize_L2=normalize_L2)
+        self.score_threshold=VECTOR_SEARCH_SCORE_THRESHOLD
+        self.chunk_size = CHUNK_SIZE
+        self.chunk_conent = False
 
     def seperate_list(self, ls: List[int]) -> List[List[int]]:
         # TODO: 增加是否属于同一文档的判断