Question

To be done in Python 3.7

Some Web sites impose certain rules for passwords. Write a function that checks whether a string is a valid password. Suppose the password rules are as follows:

• A password must have at least eight characters.

• A password must consist of only letters and digits.

• A password must contain at least two digits.

Write a program that prompts the user to enter a password and displays valid password if the rules are followed or invalid password otherwise.

• A password cannot contain the word ‘password’
• A password cannot end with ‘123’

Your program should define a class called Password, which is in its own file called password.py. You should have another file called assn13-task2.py that has code the creates and uses a Password object. All input and print functions should be in in this file. Your program will prompt the user for a password, and after completing will ask the user if they want to enter another. The program should only ever create one instance of Password. Your Password class should have at least the following:

• setPassword() method
• isValid() method
  • This should return a Boolean
• getErrorMessage() method
  • This should return a string that indicates all problems with the password
  • It should be called if isValid() returns False
  • The isValid() method can generate this string as it tests each password requirement
    • Hint: create a private instance variable called __message to save it
  • Example return string
    • “must have 8 characters\nmust have at least 2 digits\ncannot end in 123”

Answer 1

password.py file:

Code for the above password.py file:

class Password:
    __message = ''
    errorMessage = []
    def setPassword(self,passString):
        self.__message = passString
        return self.isValid()

    def getErrorMessage(self):
        temp = self.errorMessage.copy()
        self.errorMessage = []
        return temp

    def isValid(self):
        v=0
        if self.__message == 'password':
            self.errorMessage.append('A password cannot contain the word ‘password’')
            v=1
        if len(self.__message)>8:
            if self.__message[-3:] == '123':
                self.errorMessage.append('A password cannot end with ‘123’')
                v=1
        else:
            self.errorMessage.append('A password must have at least eight characters.')
            v=1
        if not self.__message.isalnum():
            self.errorMessage.append('A password must consist of only letters and digits.')
            v=1
        if sum(character.isdigit() for character in self.__message) < 2:
            self.errorMessage.append('A password must contain at least two digits.')
            v=1
        return True if v==0 else self.getErrorMessage()

assn13-task2.py file:

Code for the above assn13-task2.py file:

from Password  import Password
p = Password()
exit = 1
while(exit!=0):
    print('\nEnter password: ', end="")
    res = p.setPassword(input().strip())
    if res == True:
        print('Entered String is a Valid Password')
    else:
        for i in res:
            print(i)
    print('\nDo you want to check another password(1=>yes / 0=>no): ',end=" ")
    exit = int(input())

Output for running the  assn13-task2.py file: