droplastn() — langchain Function Reference

Architecture documentation for the droplastn() function in list.py from the langchain codebase.

Function python OutputParsing StreamingParsers called by 2

Entity Profile

OutputParsing→ StreamingParsers→ droplastn() — langchain Function Reference

Dependency Diagram

graph TD
  f91d2284_c18b_537d_db04_d69b6ec85ef7["droplastn()"]
  39460b97_96ad_60ff_34e4_145e3ec6b305["list.py"]
  f91d2284_c18b_537d_db04_d69b6ec85ef7 -->|defined in| 39460b97_96ad_60ff_34e4_145e3ec6b305
  f80a51cd_11c2_9fd1_6239_43804a539ce4["_transform()"]
  f80a51cd_11c2_9fd1_6239_43804a539ce4 -->|calls| f91d2284_c18b_537d_db04_d69b6ec85ef7
  737ee74b_6bba_9e83_2e9f_425453da49b1["_atransform()"]
  737ee74b_6bba_9e83_2e9f_425453da49b1 -->|calls| f91d2284_c18b_537d_db04_d69b6ec85ef7
  style f91d2284_c18b_537d_db04_d69b6ec85ef7 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/output_parsers/list.py lines 23–40

def droplastn(
    iter: Iterator[T],  # noqa: A002
    n: int,
) -> Iterator[T]:
    """Drop the last `n` elements of an iterator.

    Args:
        iter: The iterator to drop elements from.
        n: The number of elements to drop.

    Yields:
        The elements of the iterator, except the last n elements.
    """
    buffer: deque[T] = deque()
    for item in iter:
        buffer.append(item)
        if len(buffer) > n:
            yield buffer.popleft()