langchain/document_loaders/bibtex.py/BibtexLoader/__init__
class BibtexLoader:    def __init__(
        self,
        file_path: str,
        *,
        parser: Optional[BibtexparserWrapper] = None,
        max_docs: Optional[int] = None,
        max_content_chars: Optional[int] = 4_000,
        load_extra_metadata: bool = False,
        file_pattern: str = r"[^:]+\.pdf",
    ):
        """Initialize the BibtexLoader.

        Args:
            file_path: Path to the bibtex file.
            max_docs: Max number of associated documents to load. Use -1 means
                           no limit.
        """
        self.file_path = file_path
        self.parser = parser or BibtexparserWrapper()
        self.max_docs = max_docs
        self.max_content_chars = max_content_chars
        self.load_extra_metadata = load_extra_metadata
        self.file_regex = re.compile(file_pattern)