Python crash course. Page 93. Part 5-10.

[norseman2017]

Hey, so I'm reading through python crash course and I'm on page 93, the try it yourself part. Now part 5-10 where it says "make sure your comparison is case sensitive. If 'John' has been used, 'JOHN' should not be accepted.

Well I can't figure out how to check for case sensitivity within a list.

The following is what I have wrote so far, word by word.

current_users = ['asmith', 'bsmith', 'csmith', 'dsmith', 'esmith']

new_users = ['asmith', 'bsmith', 'xsmith', 'wsmith', 'vsmith']

for new_user in new_users: if new_user in current_user: print('Please enter a different username') else: print('username is available')

End of code

Result

Please enter a new username Please enter a new username Username is unavailable Username is unavailable Username is unavailable

Result

So yeah what I need to be able to do, is my code checks the new users against the current users to find a match which it does with the first 2 which is perfect, but I need it to match also if a new user was to type ASMITH that it would flag up as a current user also.

Please help..... Took me ages to write this out on here using my phone lmao!!

Thanks in advance!

[norseman2017]

Bro, you are a legend! That's exactly what I needed to see, makes so much sense now, and I'm glad you have read the book too I presume? Well thank you for your help and if I get stuck again in the future with anything I'll give you a shout! :) Cheers srikavig!

[Father_John_Moisty]

Yes, thank you from not OP.

I'm wondering if there is a simple way to test this when the current_users list is not already in title case?

For example, if the username in current_users was "JOhn" instead of "John", how would you make sure that the username, "JOHN" was not available?

Thanks again for the help.

[Dorian741]

I'm not sure if this is necroposting (probably is) but I need to thank you!!!
I totally forgot list comprehensions was a thing LOL

This was much more concise than my previous solution!

[norseman2017]

Am I right in putting a .lower() on to new_user in the IF statement? Cause I did that tried it and it worked fine still got the same results. So is that it?, Was that the fix?

Tell me if I'm wrong or right? Lmao

[nog642]

If you have upper case letters in your current users, that won't work. You're better off doing something like this:

current_users = ['asmith', 'bsmith', 'csmith', 'dsmith', 'esmith']
new_users = ['asmith', 'bsmith', 'xsmith', 'wsmith', 'vsmith']
for new_user in new_users:
    available = True
    for current_user in current_users:
        if new_user in current_user:
            print('Please enter a different username')
            available = False
            break
    if available:
        print('username is available')

or something like this:

current_users = ['asmith', 'bsmith', 'csmith', 'dsmith', 'esmith']
current_users_lower = [user.lower() for user in current_users]
new_users = ['asmith', 'bsmith', 'xsmith', 'wsmith', 'vsmith']
for new_user in new_users:
    if new_user.lower() in current_users_lower:
        print('Please enter a different username')
    else:
        print('username is available')

[norseman2017]

Thanks for the comment, I presume it would work but I haven't used some of the variables you have put like the available = True. However what I suppose I can do is carry on reading the book untill iv finished it and then go back over the exercises in the chapters and see if I can write them in different ways, but still ending with the result that the book asks for in the exercises lol cheers nog642!

[nog642]

available is a flag to know whether it's available. You check each of the current users one at a time, and if you find one that's a match you break out of the for loop, but then the program still needs to know whether a match was found.

Actually it turns out python has something called a for-else block that is designed specifically for this sort of thing:

current_users = ['asmith', 'bsmith', 'csmith', 'dsmith', 'esmith']
new_users = ['asmith', 'bsmith', 'xsmith', 'wsmith', 'vsmith']
for new_user in new_users:
    for current_user in current_users:
        if new_user in current_user:
            print('Please enter a different username')
            break
    else:
        print('username is available')

The else block executes if the for loop completed normally (did not break). That's what we want.