there is a DataFrame of cast which contains title, year, name, character, n.. etc.
How many leading (n=1) roles were available to actors, and how many to actresses, in each year of the 1950s?
List the 10 actors/actresses that have the most leading roles (n=1) since the 1990's.
List, in order by year, each of the films in which Frank Oz has played more than 1 role.
The questions above this line unfortunately I did not succeed.
I tried some functions in pandas but, no one fit to these questions
I would be delighted if someone could help