langchain/libs/text-splitters
Ahmed Tammaa f23c3e2444
text-splitters[patch]: Refactor HTMLHeaderTextSplitter for Enhanced Maintainability and Readability (#29397)
Please see PR #27678 for context

## Overview

This pull request presents a refactor of the `HTMLHeaderTextSplitter`
class aimed at improving its maintainability and readability. The
primary enhancements include simplifying the internal structure by
consolidating multiple private helper functions into a single private
method, thereby reducing complexity and making the codebase easier to
understand and extend. Importantly, all existing functionalities and
public interfaces remain unchanged.

## PR Goals

1. **Simplify Internal Logic**:
- **Consolidation of Private Methods**: The original implementation
utilized multiple private helper functions (`_header_level`,
`_dom_depth`, `_get_elements`) to manage different aspects of HTML
parsing and document generation. This fragmentation increased cognitive
load and potential maintenance overhead.
- **Streamlined Processing**: By merging these functionalities into a
single private method (`_generate_documents`), the class now offers a
more straightforward flow, making it easier for developers to trace and
understand the processing steps. (Thanks to @eyurtsev)

2. **Enhance Readability**:
- **Clearer Method Responsibilities**: With fewer private methods, each
method now has a more focused responsibility. The primary logic resides
within `_generate_documents`, which handles both HTML traversal and
document creation in a cohesive manner.
- **Reduced Redundancy**: Eliminating redundant checks and consolidating
logic reduces the code's verbosity, making it more concise without
sacrificing clarity.

3. **Improve Maintainability**:
- **Easier Debugging and Extension**: A simplified internal structure
allows for quicker identification of issues and easier implementation of
future enhancements or feature additions.
- **Consistent Header Management**: The new implementation ensures that
headers are managed consistently within a single context, reducing the
likelihood of bugs related to header scope and hierarchy.

4. **Maintain Backward Compatibility**:
- **Unchanged Public Interface**: All public methods (`split_text`,
`split_text_from_url`, `split_text_from_file`) and their signatures
remain unchanged, ensuring that existing integrations and usage patterns
are unaffected.
- **Preserved Docstrings**: Comprehensive docstrings are retained,
providing clear documentation for users and developers alike.

## Detailed Changes

1. **Removed Redundant Private Methods**:
- **Eliminated `_header_level`, `_dom_depth`, and `_get_elements`**:
These methods were merged into the `_generate_documents` method,
centralizing the logic for HTML parsing and document generation.

2. **Consolidated Document Generation Logic**:
- **Single Private Method `_generate_documents`**: This method now
handles the entire process of parsing HTML, tracking active headers,
managing document chunks, and yielding `Document` instances. This
consolidation reduces the number of moving parts and simplifies the
overall processing flow.

3. **Simplified Header Management**:
- **Immediate Header Scope Handling**: Headers are now managed within
the traversal loop of `_generate_documents`, ensuring that headers are
added or removed from the active headers dictionary in real-time based
on their DOM depth and hierarchy.
- **Removed `chunk_dom_depth` Attribute**: The need to track chunk DOM
depth separately has been eliminated, as header scopes are now directly
managed within the traversal logic.

4. **Streamlined Chunk Finalization**:
- **Enhanced `finalize_chunk` Function**: The chunk finalization process
has been simplified to directly yield a single `Document` when needed,
without maintaining an intermediate list. This change reduces
unnecessary list operations and makes the logic more straightforward.

5. **Improved Variable Naming and Flow**:
- **Descriptive Variable Names**: Variables such as `current_chunk` and
`node_text` provide clear insights into their roles within the
processing logic.
- **Direct Header Removal Logic**: Headers that are out of scope are
removed immediately during traversal, ensuring that the active headers
dictionary remains accurate and up-to-date.

6. **Preserved Comprehensive Docstrings**:
- **Unchanged Documentation**: All existing docstrings, including
class-level and method-level documentation, remain intact. This ensures
that users and developers continue to have access to detailed usage
instructions and method explanations.

## Testing

All existing test cases from `test_html_header_text_splitter.py` have
been executed against the refactored code. The results confirm that:

- **Functionality Remains Intact**: The splitter continues to accurately
parse HTML content, respect header hierarchies, and produce the expected
`Document` objects with correct metadata.
- **Backward Compatibility is Maintained**: No changes were required in
the test cases, and all tests pass without modifications, demonstrating
that the refactor does not introduce any regressions or alter existing
behaviors.


This example remains fully operational and behaves as before, returning
a list of `Document` objects with the expected metadata and content
splits.

## Conclusion

This refactor achieves a more maintainable and readable codebase by
simplifying the internal structure of the `HTMLHeaderTextSplitter`
class. By consolidating multiple private methods into a single, cohesive
private method, the class becomes easier to understand, debug, and
extend. All existing functionalities are preserved, and comprehensive
tests confirm that the refactor maintains the expected behavior. These
changes align with LangChain’s standards for clean, maintainable, and
efficient code.

---

---------

Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
2025-03-28 15:36:00 -04:00
..
langchain_text_splitters text-splitters[patch]: Refactor HTMLHeaderTextSplitter for Enhanced Maintainability and Readability (#29397) 2025-03-28 15:36:00 -04:00
scripts multiple: pydantic 2 compatibility, v0.3 (#26443) 2024-09-13 14:38:45 -07:00
tests text-splitters: Add JSFrameworkTextSplitter for Handling JavaScript Framework Code (#28972) 2025-03-17 23:32:33 +00:00
extended_testing_deps.txt multiple: get rid of pyproject extras (#22581) 2024-06-06 15:45:22 -07:00
Makefile infra: migrate to uv (#29566) 2025-02-06 13:36:26 -05:00
pyproject.toml text-splitters: release 0.3.7 (#30347) 2025-03-18 19:11:37 +00:00
README.md docs: more api ref links, add linting step to prevent more (#28495) 2024-12-04 04:19:42 +00:00
uv.lock text-splitters: release 0.3.7 (#30347) 2025-03-18 19:11:37 +00:00

🦜✂️ LangChain Text Splitters

Downloads License: MIT

Quick Install

pip install langchain-text-splitters

What is it?

LangChain Text Splitters contains utilities for splitting into chunks a wide variety of text documents.

For full documentation see the API reference and the Text Splitters module in the main docs.

📕 Releases & Versioning

langchain-text-splitters is currently on version 0.0.x.

Minor version increases will occur for:

  • Breaking changes for any public interfaces NOT marked beta

Patch version increases will occur for:

  • Bug fixes
  • New features
  • Any changes to private interfaces
  • Any changes to beta features

💁 Contributing

As an open-source project in a rapidly developing field, we are extremely open to contributions, whether it be in the form of a new feature, improved infrastructure, or better documentation.

For detailed information on how to contribute, see the Contributing Guide.