Question

Write a program that asks the user to enter a password, and then checks it for a few different requirements before approving it as secure and repeating the final password to the user.

The program must re-prompt the user until they provide a password that satisfies all of the conditions. It must also tell the user each of the conditions they failed, and how to fix it.
If there is more than one thing wrong (e.g., no lowercase, and longer than 15 characters), the program must print out all of the things that are wrong, and how to fix them.

The program follows these rules for passwords:

1. The password must contain at least one lowercase letter.

2. The password must contain at least one uppercase letter.

3. The password must be between 6 and 20 characters, inclusive.

   a. If the password is between 6 and 13 characters, inclusive, it must contain a “7” somewhere in the password.

   b. If the password is between 14 and 20 characters, inclusive, itmust contain a “2” somewhere in the password.

4. The password cannot contain the characters “0” and “O” (zero anduppercase o) at the same time. (It can contain a “0” or an “O”, just notboth at the same time. It may also contain neither.)

For this part of the homework, you must have an in-line comment at the top of each of your program’s individual if, elif, and else statements, explaining what is being checked by that conditional.

(HINT: Think carefully about what your conditionals should look like. If necessary, draw a truth table to help figure out what different inputs will do. Using a Boolean flag will also likely make this easier.)

(See the next page for sample output.)

Here is some sample output for hw4_part3.py, with the user input in blue. (Yours does not have to match this word for word, but it should be similar.)

linux1[8]% python hw4_part3.py
Please enter a password: dogs
Password must have an uppercase character
Password must be at least 6 characters
Please enter a password: DOGS
Password must have a lowercase character
Password must be at least 6 characters
Please enter a password: Dogs
Password must be at least 6 characters
Please enter a password: Doggos
Shorter passwords must contain a 7
Please enter a password: 7Doggos
Thank you for picking the secure password 7Doggos

linux1[9]% python hw4_part3.py
Please enter a password: thisMustBeSecureItsLongAlso27Password must be no longer than 20 characters
Please enter a password: abcdefghijklmnopqrst
Password must have an uppercase character
Longer passwords must contain a 2
Please enter a password: 2and7EQUALSnine
Thank you for picking the secure password 2and7EQUALSnine

linux1[10]%  python hw4_part3.py
Please enter a password: O_and_0
Shorter passwords must contain a 7
Password cannot contain a O and a 0 at the same time
Please enter a password: O_and_7

Thank you for picking the secure password O_and_7

linux1[11]% python hw4_part3.py
Please enter a password: greatPassword7!
Longer passwords must contain a 2
Please enter a password: greatPassword2!
Thank you for picking the secure password greatPassword2!

Answer 1

Make sure code is indented.

import re

def validate():

while True:

password = input("Enter a password: ")

if len(password) < 6 or len(password) > 20:

print("Password should be greater than or equal to 6 and less than or equal to 20")

validate()

elif len(password) >= 6 and len(password) <= 13:

if password.find("7") == -1:

print("It should have 7")

validate()

else:

r_p = re.compile('^(?=\S{6,20}$)(?=.*?\d)(?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^A-Za-z\s0-9])')

if re.search(r_p, password):

print("Valid")

break

else:

print("Invalid!")

validate()

validate()