Function cached_cumsum

dask/utils.py:2125–2151

Compute :meth:`toolz.accumulate` with caching. Caching is by the identify of `seq` rather than the value. It is thus important that `seq` is a tuple of immutable objects, and this function is intended for use where `seq` is a value that will persist (generally block sizes). Par

(seq, initial_zero=False)

def cached_cumsum(seq, initial_zero=False):
    """Compute :meth:`toolz.accumulate` with caching.

    Caching is by the identify of `seq` rather than the value. It is thus
    important that `seq` is a tuple of immutable objects, and this function
    is intended for use where `seq` is a value that will persist (generally
    block sizes).

    Parameters
    ----------
    seq : tuple
        Values to cumulatively sum.
    initial_zero : bool, optional
        If true, the return value is prefixed with a zero.

    Returns
    -------
    tuple
    """
    if isinstance(seq, tuple):
        # Look up by identity first, to avoid a linear-time __hash__
        # if we've seen this tuple object before.
        result = _cumsum(_HashIdWrapper(seq), initial_zero)
    else:
        # Construct a temporary tuple, and look up by value.
        result = _cumsum(tuple(seq), initial_zero)
    return result


def show_versions() -> None: