Python qwerty keyboard checker

Question

I am creating a code which checks a user inputted password and gives points based on it. One of the points is: If it has 3 letters adjacent/consecutive on the QWERTY UK keyboard then it will be -5 points. e.g "qwerty" will be -20 points for "qwe" "wer "ert" "rty". I have got a solution to this but I was wondering if there is any way of improving it.

input = input("What is your password?")
qwerty = 'qwertyuiopasdfghjklzxcvbnm'
lower = input.lower()
for idx in range(0, len(lower) - 2):
    test_seq = lower[idx:idx + 3]
    if test_seq in qwerty:
        points -= 5
print(points)

Answer 1

According to my interpretation, your solution does not actually meet the specification:

If it has 3 letters adjacent/consecutive on the QWERTY UK keyboard then it will be -5 points

For example, pas does not have three adjacent keys on a QWERTY keyboard, yet it gets penalized by your code. On the other hand, your code fails to detect backwards adjacent sequences such as ewq.

Answer 2

Instead of iterating over the entire string for every sequence of 3 characters, you can create a set of all possible 3-letter sequences on the QWERTY UK keyboard beforehand, and then check if any of those sequences exist in the user's inputted password.

input_password = input("What is your password?")
qwerty_sequences = {'qwe', 'wer', 'ert', 'rty', 'tyu', 'yui', 'uio', 
'iop', 'asd', 'sdf', 'dfg', 'fgh', 'ghj', 'hjk', 'jkl', 'zxc', 'xcv', 
'cvb', 'vbn', 'bnm'}
lower_password = input_password.lower()

points = 0
for seq in qwerty_sequences:
if seq in lower_password:
    points -= 5

print(points)

This implementation creates a set of all possible 3-letter sequences on the QWERTY UK keyboard and then iterates over each sequence, checking if it exists in the user's inputted password.

I've created the website keyboardtester.io by using the same concept.

Answer 3

I am sure your code works, but you missed initializing points to zero in what you shared here.

You can write these 2 lines:

input = input("What is your password?")
lower = input.lower()

into a single one:

lowercase_password = input('What is your password?').lower()

Your current program accepts short passwords, including empty strings which makes your passwords vulnerable to to attacks such as password guessing and brute force. To remedy to that, you can improve your code with:

password_length = 0
while(password_length < 16): # Change 16 to what is acceptable by the security standards
   lowercase_password = input('What is your password? ').lower()
   password_length = len(lower)

There are other elements to take in consideration if your goal is to assess the strength of a password.