Exercise

Stacking basetables

In the previous exercise you constructed two basetables basetable_january_2017 and basetable_january_2018 that correspond to two snapshots with target periods January 2017 and January 2018, respectively. In order to have enough data, another snapshot is added, resulting in basetable_january_2016. In this exercise, you will learn to construct the final basetable by stacking the basetables, and verify that there are enough observations in it.

Instructions

100 XP

Construct a basetable by adding basetable_january_2017 to basetable_january_2016.
Add basetable_january_2018 to basetable.
Print the number of observations in the final basetable.