Lowercase all strings in a list by list comprehension

Question

I am confused on how my code is not turning all strings into lowercase?

def set_lowercase(strings):
    """ lower the case 2. """
    return [i.lower() for i in strings]


strings = ['Right', 'SAID', 'Fred']
set_lowercase(strings)
print(strings)

Answer 1

You need to assign the result of your function call to the variable strings:

strings = set_lowercase(strings)

Answer 2

set_lowercase(strings) doesn't modify the input in-place.
It returns a list of strings.

So, write strings = set_lowercase(strings) instead.

Answer 3

Your function builds a new list and returns it, but the calling code doesn't do anything with the returned value.