fix:csv_loader bug

1.add new_csv_loader,override load()
2.add loader dir
Close #396

pilot/embedding_engine/loader/csv_loader.py

@@ -0,0 +1,76 @@
+"""Loads a CSV file into a list of documents.
+
+Each document represents one row of the CSV file. Every row is converted into a
+key/value pair and outputted to a new line in the document's page_content.
+
+The source for each document loaded from csv is set to the value of the
+`file_path` argument for all doucments by default.
+You can override this by setting the `source_column` argument to the
+name of a column in the CSV file.
+The source of each document will then be set to the value of the column
+with the name specified in `source_column`.
+
+Output Example:
+    .. code-block:: txt
+
+        column1: value1
+        column2: value2
+        column3: value3
+"""
+from typing import Optional, Dict, List
+import csv
+from langchain.document_loaders.base import BaseLoader
+from langchain.schema import Document
+
+
+class NewCSVLoader(BaseLoader):
+    def __init__(
+            self,
+            file_path: str,
+            source_column: Optional[str] = None,
+            csv_args: Optional[Dict] = None,
+            encoding: Optional[str] = None,
+    ):
+        """
+
+        Args:
+            file_path: The path to the CSV file.
+            source_column: The name of the column in the CSV file to use as the source.
+              Optional. Defaults to None.
+            csv_args: A dictionary of arguments to pass to the csv.DictReader.
+              Optional. Defaults to None.
+            encoding: The encoding of the CSV file. Optional. Defaults to None.
+        """
+        self.file_path = file_path
+        self.source_column = source_column
+        self.encoding = encoding
+        self.csv_args = csv_args or {}
+
+    def load(self) -> List[Document]:
+        """Load data into document objects."""
+
+        docs = []
+        with open(self.file_path, newline="", encoding=self.encoding) as csvfile:
+            csv_reader = csv.DictReader(csvfile, **self.csv_args)  # type: ignore
+            for i, row in enumerate(csv_reader):
+                strs = []
+                for k, v in row.items():
+                    if k is None or v is None:
+                        continue
+                    strs.append(f"{k.strip()}: {v.strip()}")
+                content = "\n".join(strs)
+                try:
+                    source = (
+                        row[self.source_column]
+                        if self.source_column is not None
+                        else self.file_path
+                    )
+                except KeyError:
+                    raise ValueError(
+                        f"Source column '{self.source_column}' not found in CSV file."
+                    )
+                metadata = {"source": source, "row": i}
+                doc = Document(page_content=content, metadata=metadata)
+                docs.append(doc)
+
+        return docs