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langchain-python/langchain/document_loaders/csv_loader.py
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Leonid Ganeline 1feac83323 docstrings document_loaders 2 (#6890)
updated docstring for the `document_loaders`

Maintainer responsibilities:
  - DataLoaders / VectorStores / Retrievers: @rlancemartin, @eyurtsev
2023-07-02 12:14:22 -07:00

101 lines
3.5 KiB
Python

import csv
from typing import Any, Dict, List, Optional
from langchain.docstore.document import Document
from langchain.document_loaders.base import BaseLoader
from langchain.document_loaders.unstructured import (
UnstructuredFileLoader,
validate_unstructured_version,
)
class CSVLoader(BaseLoader):
"""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
"""
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):
content = "\n".join(f"{k.strip()}: {v.strip()}" for k, v in row.items())
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
class UnstructuredCSVLoader(UnstructuredFileLoader):
"""Loader that uses unstructured to load CSV files."""
def __init__(
self, file_path: str, mode: str = "single", **unstructured_kwargs: Any
):
"""
Args:
file_path: The path to the CSV file.
mode: The mode to use when loading the CSV file.
Optional. Defaults to "single".
**unstructured_kwargs: Keyword arguments to pass to unstructured.
"""
validate_unstructured_version(min_unstructured_version="0.6.8")
super().__init__(file_path=file_path, mode=mode, **unstructured_kwargs)
def _get_elements(self) -> List:
from unstructured.partition.csv import partition_csv
return partition_csv(filename=self.file_path, **self.unstructured_kwargs)