Checked other resources

• I added a very descriptive title to this issue.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).
• I posted a self-contained, minimal, reproducible example. A maintainer can copy it and run it AS IS.

Example Code

The following code returns urls that are not properly stripped.

loader = SitemapLoader(
	"https://docs.snowflake.com/sitemap.xml",
	filter_urls=["https://docs.snowflake.com/en/sql-reference-data-types"]
)
data = loader.load()
print(data[0].metadata)

Error Message and Stack Trace (if applicable)

No response

Description

The result of that query returns URLs that are not stripped.
{'source': '\n https://docs.snowflake.com/en/sql-reference-data-types\n ', 'loc': '\n https://docs.snowflake.com/en/sql-reference-data-types\n '}

They should instead be as follows:
{'source': 'https://docs.snowflake.com/en/sql-reference-data-types', 'loc': 'https://docs.snowflake.com/en/sql-reference-data-types'}

System Info

System Information

OS: Darwin
OS Version: Darwin Kernel Version 24.3.0: Thu Jan 2 20:22:58 PST 2025; root:xnu-11215.81.4~3/RELEASE_ARM64_T8132
Python Version: 3.11.11 (main, Feb 13 2025, 11:29:41) [Clang 16.0.0 (clang-1600.0.26.6)]

Package Information

langchain_core: 0.3.51
langchain: 0.3.23
langchain_community: 0.3.21
langsmith: 0.3.28
langchain_text_splitters: 0.3.8

Optional packages not installed

langserve

Other Dependencies

aiohttp<4.0.0,>=3.8.3: Installed. No version info available.
async-timeout<5.0.0,>=4.0.0;: Installed. No version info available.
dataclasses-json<0.7,>=0.5.7: Installed. No version info available.
httpx: 0.27.2
httpx-sse<1.0.0,>=0.4.0: Installed. No version info available.
jsonpatch<2.0,>=1.33: Installed. No version info available.
langchain-anthropic;: Installed. No version info available.
langchain-aws;: Installed. No version info available.
langchain-azure-ai;: Installed. No version info available.
langchain-cohere;: Installed. No version info available.
langchain-community;: Installed. No version info available.
langchain-core<1.0.0,>=0.3.51: Installed. No version info available.
langchain-deepseek;: Installed. No version info available.
langchain-fireworks;: Installed. No version info available.
langchain-google-genai;: Installed. No version info available.
langchain-google-vertexai;: Installed. No version info available.
langchain-groq;: Installed. No version info available.
langchain-huggingface;: Installed. No version info available.
langchain-mistralai;: Installed. No version info available.
langchain-ollama;: Installed. No version info available.
langchain-openai;: Installed. No version info available.
langchain-perplexity;: Installed. No version info available.
langchain-text-splitters<1.0.0,>=0.3.8: Installed. No version info available.
langchain-together;: Installed. No version info available.
langchain-xai;: Installed. No version info available.
langchain<1.0.0,>=0.3.23: Installed. No version info available.
langsmith-pyo3: Installed. No version info available.
langsmith<0.4,>=0.1.125: Installed. No version info available.
langsmith<0.4,>=0.1.17: Installed. No version info available.
numpy<3,>=1.26.2: Installed. No version info available.
openai-agents: Installed. No version info available.
opentelemetry-api: 1.27.0
opentelemetry-exporter-otlp-proto-http: Installed. No version info available.
opentelemetry-sdk: 1.27.0
orjson: 3.10.7
packaging: 24.1
packaging<25,>=23.2: Installed. No version info available.
pydantic: 2.11.3
pydantic-settings<3.0.0,>=2.4.0: Installed. No version info available.
pydantic<3.0.0,>=2.5.2;: Installed. No version info available.
pydantic<3.0.0,>=2.7.4: Installed. No version info available.
pydantic<3.0.0,>=2.7.4;: Installed. No version info available.
pytest: 8.3.3
PyYAML>=5.3: Installed. No version info available.
requests: 2.32.3
requests-toolbelt: 1.0.0
requests<3,>=2: Installed. No version info available.
rich: 14.0.0
SQLAlchemy<3,>=1.4: Installed. No version info available.
tenacity!=8.4.0,<10,>=8.1.0: Installed. No version info available.
tenacity!=8.4.0,<10.0.0,>=8.1.0: Installed. No version info available.
typing-extensions>=4.7: Installed. No version info available.
zstandard: 0.23.0