How do I make all words in a list of words lowercase in python? [duplicate]

I'm trying to make all entries in my list dictionary lowercase but I cant figure out a way to do this

def get_entire_word_list():
dictionary = []
f = open("dictionary.txt", "r")
for x in f:
    dictionary.append(x.strip('\n'))

f.close()

for x in dictionary:
    x.lower()

for x in dictionary:
    print(x)

return dictionary

This just won't do it :(

I tried

for x in dictionary:
    x = x.lower()

but that wont do it either.

Thanks for any tips

If you have a list of strings, called dictionary, you can use a list comprehension like

dictionary = [x.lower() for x in dictionary]

to create a new list that contains only lowered cased string.