I need to write a function named older_people(people: list, year: int), which selects all those people on the list who were born before the year given as an argument. The function should return the names of these people in a new list.

An example of its use:

p1 = ("Adam", 1977)
p2 = ("Ellen", 1985)
p3 = ("Mary", 1953)
p4 = ("Ernest", 1997)
people = [p1, p2, p3, p4]

older = older_people(people, 1979)
print(older)

Sample output:
[ ‘Adam’, ‘Mary’ ]

So far I got:

    def older_people(people: list, year: int):

        for person in plist:
            if person[1] < year:
                return person[0]
 



    p1 = ("Adam", 1977)
    p2 = ("Ellen", 1985)
    p3 = ("Mary", 1953)
    p4 = ("Ernest", 1997)
    plist = [p1, p2, p3, p4]

    older = older_people(plist, 1979)
    print(older)

At the moment this just prints the first person (Adam) who is born before 1979.
Any help for this one?

>Solution :

First you should use the argument of the function in the body of older_people instead of the global variable plist. people should be used instead of plist.

Then, your return statement is inside the for loop, this means that it will leave the function at the first time the if condition is true, hence printing only one person.

def older_people(people: list, year: int):
    result = []
    for person in people:
        if person[1] < year:
         result.append(person[0])
    return result




p1 = ("Adam", 1977)
p2 = ("Ellen", 1985)
p3 = ("Mary", 1953)
p4 = ("Ernest", 1997)
plist = [p1, p2, p3, p4]

older = older_people(plist, 1979)
print(older)