dask.bag.Bag.accumulate

Bag.accumulate(binop, initial='__no__default__')[source]

Repeatedly apply binary function to a sequence, accumulating results.

This assumes that the bag is ordered. While this is typically the case not all Dask.bag functions preserve this property.

Examples

>>> import dask.bag as db
>>> from operator import add
>>> b = db.from_sequence([1, 2, 3, 4, 5], npartitions=2)
>>> b.accumulate(add).compute()
[1, 3, 6, 10, 15]

Accumulate also takes an optional argument that will be used as the first value.

>>> b.accumulate(add, initial=-1).compute()
[-1, 0, 2, 5, 9, 14]