Агрегирование значений

first и last

more_itertools.first(iterable[, default])
more_itertools.last(iterable[, default])

In [42]: data = [1, 2, 'a', 'b', 5, 'c', 7]

In [43]: more_itertools.first(data)
Out[43]: 1

In [44]: more_itertools.last(data)
Out[44]: 7

all_equal

more_itertools.all_equal(iterable)

In [46]: more_itertools.all_equal([1, 1, 1])
Out[46]: True

In [47]: more_itertools.all_equal([1, 2, 1])
Out[47]: False