Error: TypeError: 'str' object cannot be interpreted as an integer while trying to pick a random winner (Python)

If you want to remove an item from a list, use the .remove() function like so:

>>> winners = ["a", "b", "c"]
>>> winners.remove("b")
>>> winners
['a', 'c']

.pop() is used to extract an element from a list based on the index given, and returns the element removed from the list. Your error appears because you're trying to pop based off an element in the list (a name), as opposed to its index (its position in the list).

If you want to stick with pop, perhaps instead of choosing a random name, choose a random index in the list:

winners = ["Wane", "Trevor", "Franklin", "Martoz"]
winner = winners.pop(random.randrange(len(winners)))

If you provide an argument for method list.pop, that argument must be of type integer and represent the index of the element in the list.

Since your call looks like

winners.pop(winner)

and winner is a string, you'll get the mentioned error

TypeError: 'str' object cannot be interpreted as an integer

Also, I'm not sure what you really want to do, but you probably need to have two lists participants and winners. The following example draws two winners from the list:

import random

participants = ["Wane", "Trevor", "Franklin", "Martoz"]
winners = []

print("Participants before:", participants)
print("Winners before:", winners)

winner = random.choice(participants)
winners.append(winner)
participants.remove(winner)

winner = random.choice(participants)
winners.append(winner)
participants.remove(winner)

print("Participants after:", participants)
print("Winners after:", winners)

Which prints:

Participants before: ['Wane', 'Trevor', 'Franklin', 'Martoz']
Winners before: []
Participants after: ['Wane', 'Trevor']
Winners after: ['Martoz', 'Franklin']

Instead of using .pop(), just use remove()

winners = ["Wane", "Trevor", "Franklin", "Martoz"]
winner = random.choice(winners)
winners.remove(winner)
winners.append("Michael")
print(winners)

If you want to use pop() function you should provide the index of winner in the winners list. This can be done by using winners.index(winner)

winners = ["Wane", "Trevor", "Franklin", "Martoz"]
winner = random.choice(winners)
winners.pop(winners.index(winner))
winners.append("Michael")
print(winners)

Result:

['Wane', 'Trevor', 'Martoz', 'Michael']