Update loader

Signed-off-by: shiyu22 <shiyu.chen@zilliz.com>

loader.py

@@ -1,16 +1,49 @@
 from towhee.operator import PyOperator
+from typing import List, Optional
+from langchain.docstore.document import Document
+from langchain.text_splitter import RecursiveCharacterTextSplitter
+
 
 
 class TextLoader(PyOperator):
-    """
-    DefaultOperator for _input and _output nodes.
-    """
+    '''Load data from urls or files (paths or file-like objects) as a list of doc chunks'''
+    def __init__(self,
+                 chunk_size: int = 300,
+                 source_type: str = 'file',
+                 ):
+        self.splitter = RecursiveCharacterTextSplitter(chunk_size=chunk_size)
+        self.source_type = source_type
+
+    def __call__(self, data_src) -> List[str]:
+        if not isinstance(data_src, list):
+            data_src = [data_src]
+        if self.source_type == 'file':
+            docs = self._from_files(data_src)
+        elif self.source_type == 'url':
+            docs= self._from_urls(data_src)
+        else:
+            raise AttributeError('Invalid source type. Only support "file" or "url".')
+
+        docs = self.splitter.split_documents(docs)
+        return [str(doc.page_content) for doc in docs]
 
-    def __init__(self):
-        #pylint: disable=useless-super-delegation
-        super().__init__()
+    def _from_files(self, files: list, encoding: Optional[str] = None) -> List[Document]:
+        '''Load documents from path or file-like object, return a list of unsplit Langchain Documents'''
+        docs = []
+        for file in files:
+            if hasattr(file, 'name'):
+                file_path = file.name
+            else:
+                file_path = file
+            with open(file_path, encoding=encoding) as f:
+                text = f.read()
+            metadata = {"source": file_path}
+            docs.append(Document(page_content=text, metadata=metadata))
+        return docs
+    
+    def _from_urls(self, urls: List[str]) -> List[Document]:
+        from langchain.document_loaders import UnstructuredURLLoader
 
-    def __call__(self, *args):
-        if len(args) == 1:
-            return args[0]
-        return args
+        loader = UnstructuredURLLoader(urls=urls)
+        docs = loader.load()
+        return docs

requirements.txt

@@ -0,0 +1 @@
+langchain