mirror of
https://github.com/hwchase17/langchain
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110 lines
3.8 KiB
Python
110 lines
3.8 KiB
Python
import logging
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from pathlib import Path
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from typing import Iterator, Optional, Sequence, Union
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from langchain_core.documents import Document
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from langchain_community.document_loaders.base import BaseLoader
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logger = logging.getLogger(__name__)
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class MWDumpLoader(BaseLoader):
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"""Load `MediaWiki` dump from an `XML` file.
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Example:
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.. code-block:: python
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from langchain_text_splitters import RecursiveCharacterTextSplitter
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from langchain_community.document_loaders import MWDumpLoader
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loader = MWDumpLoader(
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file_path="myWiki.xml",
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encoding="utf8"
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)
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docs = loader.load()
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text_splitter = RecursiveCharacterTextSplitter(
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chunk_size=1000, chunk_overlap=0
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)
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texts = text_splitter.split_documents(docs)
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:param file_path: XML local file path
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:type file_path: str
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:param encoding: Charset encoding, defaults to "utf8"
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:type encoding: str, optional
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:param namespaces: The namespace of pages you want to parse.
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See https://www.mediawiki.org/wiki/Help:Namespaces#Localisation
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for a list of all common namespaces
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:type namespaces: List[int],optional
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:param skip_redirects: TR=rue to skip pages that redirect to other pages,
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False to keep them. False by default
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:type skip_redirects: bool, optional
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:param stop_on_error: False to skip over pages that cause parsing errors,
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True to stop. True by default
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:type stop_on_error: bool, optional
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"""
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def __init__(
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self,
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file_path: Union[str, Path],
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encoding: Optional[str] = "utf8",
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namespaces: Optional[Sequence[int]] = None,
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skip_redirects: Optional[bool] = False,
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stop_on_error: Optional[bool] = True,
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):
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self.file_path = file_path if isinstance(file_path, str) else str(file_path)
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self.encoding = encoding
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# Namespaces range from -2 to 15, inclusive.
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self.namespaces = namespaces
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self.skip_redirects = skip_redirects
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self.stop_on_error = stop_on_error
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def _load_dump_file(self): # type: ignore[no-untyped-def]
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try:
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import mwxml
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except ImportError as e:
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raise ImportError(
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"Unable to import 'mwxml'. Please install with" " `pip install mwxml`."
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) from e
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return mwxml.Dump.from_file(open(self.file_path, encoding=self.encoding))
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def _load_single_page_from_dump(self, page) -> Document: # type: ignore[no-untyped-def, return]
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"""Parse a single page."""
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try:
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import mwparserfromhell
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except ImportError as e:
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raise ImportError(
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"Unable to import 'mwparserfromhell'. Please install with"
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" `pip install mwparserfromhell`."
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) from e
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for revision in page:
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code = mwparserfromhell.parse(revision.text)
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text = code.strip_code(
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normalize=True, collapse=True, keep_template_params=False
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)
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metadata = {"source": page.title}
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return Document(page_content=text, metadata=metadata)
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def lazy_load(
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self,
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) -> Iterator[Document]:
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"""Lazy load from a file path."""
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dump = self._load_dump_file()
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for page in dump.pages:
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if self.skip_redirects and page.redirect:
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continue
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if self.namespaces and page.namespace not in self.namespaces:
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continue
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try:
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yield self._load_single_page_from_dump(page)
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except Exception as e:
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logger.error("Parsing error: {}".format(e))
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if self.stop_on_error:
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raise e
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else:
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continue
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