Answer 1

For Python 2 map and filter returned a list object. In Python 3, map returns an iterable generator type, map object, and filter returns a filter object.

It isn't always necessary. it depends on how you wish to use it. The code below will print each mapped int without the need to convert to a list first.

nums = [11, 22, 33, 44, 55]

result = map(lambda x: x+5, nums)

for i in result:
print(i)

outputs:

16
27
38
49
60