utils.py — langchain Source File

Source Code

"""Internal utilities for the in memory implementation of `VectorStore`.

!!! warning

    These are part of a private API, and users should not use them directly as they can
    change without notice.
"""

from __future__ import annotations

import logging
import warnings
from typing import TYPE_CHECKING, cast

try:
    import numpy as np

    _HAS_NUMPY = True
except ImportError:
    _HAS_NUMPY = False

try:
    import simsimd as simd  # type: ignore[import-not-found]

    _HAS_SIMSIMD = True
except ImportError:
    _HAS_SIMSIMD = False

if TYPE_CHECKING:
    Matrix = list[list[float]] | list[np.ndarray] | np.ndarray

logger = logging.getLogger(__name__)


def _cosine_similarity(x: Matrix, y: Matrix) -> np.ndarray:
    """Row-wise cosine similarity between two equal-width matrices.

    Args:
        x: A matrix of shape `(n, m)`.
        y: A matrix of shape `(k, m)`.

    Returns:
        A matrix of shape `(n, k)` where each element `(i, j)` is the cosine similarity
            between the `i`th row of `x` and the `j`th row of `y`.

    Raises:
        ValueError: If the number of columns in `x` and `y` are not the same.
        ImportError: If numpy is not installed.
    """
    if not _HAS_NUMPY:
        msg = (
            "cosine_similarity requires numpy to be installed. "
            "Please install numpy with `pip install numpy`."
        )
        raise ImportError(msg)

    if len(x) == 0 or len(y) == 0:
        return np.array([[]])

    x = np.array(x)
// ... (98 more lines)