List logic

[Low_Ki_]

so here is another one... how do I get the \ in invalidChars list without it showing up as double \\

def getUserInfo():

    while True:
        print('Enter a valid username: ')
        username = input()
        invalidChars = '!@#$%^&*()+=~`{}|[]:;"<,.>/ ?\\'
        invalidList = []
        for l in invalidChars:
            invalidList.append(l)

        print(invalidList)
        break
getUserInfo()

Output:
Enter a valid username: 
f
['!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '+', '=', '~', '`', '{', '}', '|', '[', ']', ':', ';', '"', '<', ',', '.', '>', '/', ' ', '?', '\\']