what is the best size of chunking in langchain

[holly-21]

I want to chunk the files of github repo.
What is the best size of chunk and overlap?
Here is the code.

def main():
    github_link = input("Please enter the GitHub link : ")
    while True:
        if url_check(github_link) is True:
            print("Validation Complete API Search Initiated")
            break
        else: 
            github_link = input("The GitHub link doesn't exist. Please enter it again : ")

    github_info_dict = github_api_call(github_link, make_txt_file=False)
    
    docs = document_processing(github_info_dict, make_txt_file=False)
    texts = document_chunking(docs, size=1000, overlap=0)

[dosubot[bot]]

Answer generated by a 🤖

Answer

I understand that you're looking to determine the optimal size for chunking and overlap when processing documents in the LangChain framework. You're specifically interested in how to set these parameters when chunking files from a GitHub repository.

In LangChain, the default chunk size and overlap are defined in the TextSplitter class, which is located in the langchain/text_splitter.py file. By default, the chunk_size is set to 4000 and the chunk_overlap is set to 200. However, these values are not set in stone and can be adjusted to better suit your specific needs.

Here's the relevant section of the TextSplitter class:

class TextSplitter(BaseDocumentTransformer, ABC):
    def __init__(
        self,
        chunk_size: int = 4000,
        chunk_overlap: int = 200,
        length_function: Callable[[str], int] = len,
        keep_separator: bool = False,
        add_start_index: bool = False,
    ) -> None:
        if chunk_overlap > chunk_size:
            raise ValueError(
                f"Got a larger chunk overlap ({chunk_overlap}) than chunk size "
                f"({chunk_size}), should be smaller."
            )
        self._chunk_size = chunk_size
        self._chunk_overlap = chunk_overlap
        self._length_function = length_function
        self._keep_separator = keep_separator
        self._add_start_index = add_start_index

In your code, you can modify the size and overlap parameters in the document_chunking function to change the chunk size and overlap:

texts = document_chunking(docs, size=1000, overlap=0)

Please remember that the chunk_overlap should always be smaller than the chunk_size. If the chunk_overlap is larger than the chunk_size, a ValueError will be raised.

This is just one potential solution, and the optimal chunk size and overlap may vary depending on your specific use case and the nature of the documents you're processing.

If you find this information helpful and believe it could benefit other users, I encourage you to make a pull request to update the LangChain documentation. This way, others who may have the same question in the future can easily find this information.

Sources

• langchain/text_splitter.py

---

This response is meant to be useful, save you time, and share context. It is not meant to be a precise solution, but rather a starting point for your own research.

Help me be more useful! Please leave a 👍 if this is helpful and 👎 if it is irrelevant.

[devstein]

@holly-21 There isn't a one-size fits all solution for chunk size. It's use-case dependent. For code, I've found larger chunks (~2000 characters) is better, but more important is how you do the chunking. I highly recommend using LangChain's language specific text splitters for chunking code