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88 lines
2.7 KiB
Python
88 lines
2.7 KiB
Python
"""Abstract interface for document loader implementations."""
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from abc import ABC, abstractmethod
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from typing import Iterator, List, Optional
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from langchain.document_loaders.blob_loaders import Blob
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from langchain.schema import Document
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from langchain.text_splitter import RecursiveCharacterTextSplitter, TextSplitter
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class BaseLoader(ABC):
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"""Interface for loading documents.
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Implementations should implement the lazy-loading method using generators
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to avoid loading all documents into memory at once.
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The `load` method will remain as is for backwards compatibility, but its
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implementation should be just `list(self.lazy_load())`.
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"""
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# Sub-classes should implement this method
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# as return list(self.lazy_load()).
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# This method returns a List which is materialized in memory.
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@abstractmethod
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def load(self) -> List[Document]:
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"""Load data into document objects."""
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def load_and_split(
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self, text_splitter: Optional[TextSplitter] = None
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) -> List[Document]:
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"""Load documents and split into chunks."""
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if text_splitter is None:
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_text_splitter: TextSplitter = RecursiveCharacterTextSplitter()
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else:
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_text_splitter = text_splitter
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docs = self.load()
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return _text_splitter.split_documents(docs)
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# Attention: This method will be upgraded into an abstractmethod once it's
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# implemented in all the existing subclasses.
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def lazy_load(
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self,
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) -> Iterator[Document]:
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"""A lazy loader for document content."""
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raise NotImplementedError(
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f"{self.__class__.__name__} does not implement lazy_load()"
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)
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class BaseBlobParser(ABC):
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"""Abstract interface for blob parsers.
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A blob parser is provides a way to parse raw data stored in a blob into one
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or more documents.
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The parser can be composed with blob loaders, making it easy to re-use
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a parser independent of how the blob was originally loaded.
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"""
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@abstractmethod
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def lazy_parse(self, blob: Blob) -> Iterator[Document]:
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"""Lazy parsing interface.
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Subclasses are required to implement this method.
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Args:
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blob: Blob instance
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Returns:
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Generator of documents
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"""
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def parse(self, blob: Blob) -> List[Document]:
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"""Eagerly parse the blob into a document or documents.
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This is a convenience method for interactive development environment.
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Production applications should favor the lazy_parse method instead.
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Subclasses should generally not over-ride this parse method.
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Args:
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blob: Blob instance
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Returns:
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List of documents
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"""
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return list(self.lazy_parse(blob))
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