Removing duplicate objects

Assume that you want to construct a predictive model in order to select donors that are most likely to respond on a letter. The population of the basetable should contain donors that have an adress available, and that have privacy settings that allow to send them a letter. All candidate donors are given in a dataframe donors with three columns: the donor_id, a flag address that is 1 if the address is available and 0 otherwise, and a flag letter_allowed that is 1 if one can send this donor a letter and 0 otherwise. In this exercise you will construct a set with the donors that should go in the population.

Create a dataframe donors_population only containing observations that have address available and for which a letter is allowed.
Create a list containing the donor ids in donors_population.
Construct the final population and then numbers of donors in it.

Exercise

Removing duplicate objects

Instructions