from __future__ import annotations
from pathlib import Path
from typing import (
TYPE_CHECKING,
Any,
Iterator,
List,
Literal,
Optional,
Sequence,
Union,
)
from langchain_core.documents import Document
from langchain_community.document_loaders.base import BaseBlobParser, BaseLoader
from langchain_community.document_loaders.blob_loaders import (
BlobLoader,
FileSystemBlobLoader,
)
from langchain_community.document_loaders.parsers.registry import get_parser
if TYPE_CHECKING:
from langchain_text_splitters import TextSplitter
_PathLike = Union[str, Path]
DEFAULT = Literal["default"]
[docs]
class GenericLoader(BaseLoader):
"""Generic Document Loader.
A generic document loader that allows combining an arbitrary blob loader with
a blob parser.
Examples:
Parse a specific PDF file:
.. code-block:: python
from langchain_community.document_loaders import GenericLoader
from langchain_community.document_loaders.parsers.pdf import PyPDFParser
# Recursively load all text files in a directory.
loader = GenericLoader.from_filesystem(
"my_lovely_pdf.pdf",
parser=PyPDFParser()
)
.. code-block:: python
from langchain_community.document_loaders import GenericLoader
from langchain_community.document_loaders.blob_loaders import FileSystemBlobLoader
loader = GenericLoader.from_filesystem(
path="path/to/directory",
glob="**/[!.]*",
suffixes=[".pdf"],
show_progress=True,
)
docs = loader.lazy_load()
next(docs)
Example instantiations to change which files are loaded:
.. code-block:: python
# Recursively load all text files in a directory.
loader = GenericLoader.from_filesystem("/path/to/dir", glob="**/*.txt")
# Recursively load all non-hidden files in a directory.
loader = GenericLoader.from_filesystem("/path/to/dir", glob="**/[!.]*")
# Load all files in a directory without recursion.
loader = GenericLoader.from_filesystem("/path/to/dir", glob="*")
Example instantiations to change which parser is used:
.. code-block:: python
from langchain_community.document_loaders.parsers.pdf import PyPDFParser
# Recursively load all text files in a directory.
loader = GenericLoader.from_filesystem(
"/path/to/dir",
glob="**/*.pdf",
parser=PyPDFParser()
)
""" # noqa: E501
[docs]
def __init__(
self,
blob_loader: BlobLoader, # type: ignore[valid-type]
blob_parser: BaseBlobParser,
) -> None:
"""A generic document loader.
Args:
blob_loader: A blob loader which knows how to yield blobs
blob_parser: A blob parser which knows how to parse blobs into documents
"""
self.blob_loader = blob_loader
self.blob_parser = blob_parser
[docs]
def lazy_load(
self,
) -> Iterator[Document]:
"""Load documents lazily. Use this when working at a large scale."""
for blob in self.blob_loader.yield_blobs(): # type: ignore[attr-defined]
yield from self.blob_parser.lazy_parse(blob)
[docs]
def load_and_split(
self, text_splitter: Optional[TextSplitter] = None
) -> List[Document]:
"""Load all documents and split them into sentences."""
raise NotImplementedError(
"Loading and splitting is not yet implemented for generic loaders. "
"When they will be implemented they will be added via the initializer. "
"This method should not be used going forward."
)
[docs]
@classmethod
def from_filesystem(
cls,
path: _PathLike,
*,
glob: str = "**/[!.]*",
exclude: Sequence[str] = (),
suffixes: Optional[Sequence[str]] = None,
show_progress: bool = False,
parser: Union[DEFAULT, BaseBlobParser] = "default",
parser_kwargs: Optional[dict] = None,
) -> GenericLoader:
"""Create a generic document loader using a filesystem blob loader.
Args:
path: The path to the directory to load documents from OR the path to a
single file to load. If this is a file, glob, exclude, suffixes
will be ignored.
glob: The glob pattern to use to find documents.
suffixes: The suffixes to use to filter documents. If None, all files
matching the glob will be loaded.
exclude: A list of patterns to exclude from the loader.
show_progress: Whether to show a progress bar or not (requires tqdm).
Proxies to the file system loader.
parser: A blob parser which knows how to parse blobs into documents,
will instantiate a default parser if not provided.
The default can be overridden by either passing a parser or
setting the class attribute `blob_parser` (the latter
should be used with inheritance).
parser_kwargs: Keyword arguments to pass to the parser.
Returns:
A generic document loader.
"""
blob_loader = FileSystemBlobLoader( # type: ignore[attr-defined, misc]
path,
glob=glob,
exclude=exclude,
suffixes=suffixes,
show_progress=show_progress,
)
if isinstance(parser, str):
if parser == "default":
try:
# If there is an implementation of get_parser on the class, use it.
blob_parser = cls.get_parser(**(parser_kwargs or {}))
except NotImplementedError:
# if not then use the global registry.
blob_parser = get_parser(parser)
else:
blob_parser = get_parser(parser)
else:
blob_parser = parser
return cls(blob_loader, blob_parser)
[docs]
@staticmethod
def get_parser(**kwargs: Any) -> BaseBlobParser:
"""Override this method to associate a default parser with the class."""
raise NotImplementedError()
