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Sitemap

Extends from the WebBaseLoader, SitemapLoader loads a sitemap from a given URL, and then scrape and load all pages in the sitemap, returning each page as a Document.

The scraping is done concurrently. There are reasonable limits to concurrent requests, defaulting to 2 per second. If you aren’t concerned about being a good citizen, or you control the scrapped server, or don’t care about load. Note, while this will speed up the scraping process, but it may cause the server to block you. Be careful!

!pip install nest_asyncio
Requirement already satisfied: nest_asyncio in /Users/tasp/Code/projects/langchain/.venv/lib/python3.10/site-packages (1.5.6)

[notice] A new release of pip available: 22.3.1 -> 23.0.1
[notice] To update, run: pip install --upgrade pip
# fixes a bug with asyncio and jupyter
import nest_asyncio

nest_asyncio.apply()
from langchain.document_loaders.sitemap import SitemapLoader
sitemap_loader = SitemapLoader(web_path="https://langchain.readthedocs.io/sitemap.xml")

docs = sitemap_loader.load()

You can change the requests_per_second parameter to increase the max concurrent requests. and use requests_kwargs to pass kwargs when send requests.

sitemap_loader.requests_per_second = 2
# Optional: avoid `[SSL: CERTIFICATE_VERIFY_FAILED]` issue
sitemap_loader.requests_kwargs = {"verify": False}
docs[0]
Document(page_content='\n\n\n\n\n\n\n\n\n\nLangChain Python API Reference Documentation.\n\n\n\n\n\n\n\n\n\nYou will be automatically redirected to the new location of this page.\n\n', metadata={'source': 'https://api.python.langchain.com/en/stable/', 'loc': 'https://api.python.langchain.com/en/stable/', 'lastmod': '2023-10-13T18:13:26.966937+00:00', 'changefreq': 'weekly', 'priority': '1'})

Filtering sitemap URLs​

Sitemaps can be massive files, with thousands of URLs. Often you don’t need every single one of them. You can filter the URLs by passing a list of strings or regex patterns to the filter_urls parameter. Only URLs that match one of the patterns will be loaded.

loader = SitemapLoader(
    web_path="https://langchain.readthedocs.io/sitemap.xml",
    filter_urls=["https://api.python.langchain.com/en/latest"],
)
documents = loader.load()
Fetching pages: 100%|##########| 1/1 [00:00<00:00, 16.39it/s]
documents[0]
Document(page_content='\n\n\n\n\n\n\n\n\n\nLangChain Python API Reference Documentation.\n\n\n\n\n\n\n\n\n\nYou will be automatically redirected to the new location of this page.\n\n', metadata={'source': 'https://api.python.langchain.com/en/latest/', 'loc': 'https://api.python.langchain.com/en/latest/', 'lastmod': '2023-10-13T18:09:58.478681+00:00', 'changefreq': 'daily', 'priority': '0.9'})

Add custom scraping rules​

The SitemapLoader uses beautifulsoup4 for the scraping process, and it scrapes every element on the page by default. The SitemapLoader constructor accepts a custom scraping function. This feature can be helpful to tailor the scraping process to your specific needs; for example, you might want to avoid scraping headers or navigation elements.

The following example shows how to develop and use a custom function to avoid navigation and header elements.

Import the beautifulsoup4 library and define the custom function.

pip install beautifulsoup4
from bs4 import BeautifulSoup


def remove_nav_and_header_elements(content: BeautifulSoup) -> str:
    # Find all 'nav' and 'header' elements in the BeautifulSoup object
    nav_elements = content.find_all("nav")
    header_elements = content.find_all("header")

    # Remove each 'nav' and 'header' element from the BeautifulSoup object
    for element in nav_elements + header_elements:
        element.decompose()

    return str(content.get_text())

Add your custom function to the SitemapLoader object.

loader = SitemapLoader(
    "https://langchain.readthedocs.io/sitemap.xml",
    filter_urls=["https://api.python.langchain.com/en/latest/"],
    parsing_function=remove_nav_and_header_elements,
)

Local Sitemap​

The sitemap loader can also be used to load local files.

sitemap_loader = SitemapLoader(web_path="example_data/sitemap.xml", is_local=True)

docs = sitemap_loader.load()
Fetching pages: 100%|##########| 3/3 [00:00<00:00, 12.46it/s]