Accessing values of list using for loop

Question

name_input = 'abc'
password_input = 123

names = ['abc', 'root']
passwords = [123, 456]

for name, password in names, passwords:
    if name == name_input and password == password_input:
        print('Valid')
    else:
        print('Invalid')

Output:

Invalid 
Invalid

Expected output:

Valid 
Invalid

What's the problem with this code?

Answer 1

As pointed by enke, you need zip():

name_input = 'abc'
password_input = 123

names = ['abc', 'root']
passwords = [123, 456]

for name, password in zip(names, passwords):
    if all({name == name_input, password == password_input}):
        print('Valid')
    else:
        print('Invalid')

The code above outputs:

Valid
Invalid

As you expected.

Another option is to have a list or a dictionary of name and password pairs:

name_input = 'abc'
password_input = 123

names_and_passwords = [
    ('abc', 123),
    ('root', 456)
]

for name, password in names_and_passwords:
    if all({name == name_input, password == password_input}):
        print('Valid')
    else:
        print('Invalid')

name_input = 'abc'
password_input = 123

names_and_passwords = {
    'abc': 123,
    'root': 456
}

for name, password in names_and_passwords.items():
    if all({name == name_input, password == password_input}):
        print('Valid')
    else:
        print('Invalid')

Which gives you the same result.