The accumulate() function folds a given function into an iterable, accumulating a series of reductions. This will iterate over the running totals from another iterator; the default function is operator.add(). We can provide alternative functions to change the essential behavior from sum to product. The Python library documentation shows a particularly clever use of the max() function to create a sequence of maximum values so far.
One application of running totals is quartiling data. We can compute the running total for each sample and divide them into quarters with an int(4*value/total) calculation.
In the Assigning numbers with enumerate() section, we introduced a sequence of latitude-longitude coordinates ...
