# dask.bag.Bag.accumulate

Bag.accumulate(binop, initial=<no_default>)

  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]