How to do a case-insensitive comparison in Python?

Question

Python

It is necessary to compare 2 lines, while not taking into account the case in which they are written. The strings 'Hello' 'hello' 'HeLlO' 'hELLo' should compare as equal and output that the name is taken

current_users = ['Yaroslav', 'Misha', 'Grisha', 'Masha', 'Lilya']
new_users = ['Anna', 'Misha', 'Alex', 'Masha', 'Lilya']
for user in new_users:
    if user in current_users:
        print('Имя занято')
    else:
        print('Имя свободно')

Answer 1

When comparing the drive and those to a single register.