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langchain/langchain/document_loaders/sitemap.py

88 lines
2.6 KiB
Python

"""Loader that fetches a sitemap and loads those URLs."""
import re
from typing import Any, Callable, List, Optional
from langchain.document_loaders.web_base import WebBaseLoader
from langchain.schema import Document
def _default_parsing_function(content: Any) -> str:
return str(content.get_text())
class SitemapLoader(WebBaseLoader):
"""Loader that fetches a sitemap and loads those URLs."""
def __init__(
self,
web_path: str,
filter_urls: Optional[List[str]] = None,
parsing_function: Optional[Callable] = None,
):
"""Initialize with webpage path and optional filter URLs.
Args:
web_path: url of the sitemap
filter_urls: list of strings or regexes that will be applied to filter the
urls that are parsed and loaded
parsing_function: Function to parse bs4.Soup output
"""
try:
import lxml # noqa:F401
except ImportError:
raise ValueError(
"lxml package not found, please install it with " "`pip install lxml`"
)
super().__init__(web_path)
self.filter_urls = filter_urls
self.parsing_function = parsing_function or _default_parsing_function
def parse_sitemap(self, soup: Any) -> List[dict]:
"""Parse sitemap xml and load into a list of dicts."""
els = []
for url in soup.find_all("url"):
loc = url.find("loc")
if not loc:
continue
if self.filter_urls and not any(
re.match(r, loc.text) for r in self.filter_urls
):
continue
els.append(
{
tag: prop.text
for tag in ["loc", "lastmod", "changefreq", "priority"]
if (prop := url.find(tag))
}
)
for sitemap in soup.find_all("sitemap"):
loc = sitemap.find("loc")
if not loc:
continue
soup_child = self.scrape_all([loc.text], "xml")[0]
els.extend(self.parse_sitemap(soup_child))
return els
def load(self) -> List[Document]:
"""Load sitemap."""
soup = self.scrape("xml")
els = self.parse_sitemap(soup)
results = self.scrape_all([el["loc"].strip() for el in els if "loc" in el])
return [
Document(
page_content=self.parsing_function(results[i]),
metadata={**{"source": els[i]["loc"]}, **els[i]},
)
for i in range(len(results))
]