python - Password validity checker using python

Password validity checker using python

• You need to implement a password validity checker.  A password is valid if all the given rules are satisfied, else it is invalid.
•  At least 1 (one) lower case letter ([a-z]) is present
•  At least 1 numeric character ([0-9]) is present  
•  At least 1 (one) upper  case letter ([A-Z]) is present
•  At least 1 character from [$#@] is present
•  Minimum and Maximum length allowed must be 6 and 12 respectively
• Input : You need to read a string from STDIN and check if it is a valid or invalid password.
• Output : The string valid or invalid printed.

• Test Cases:

• Input: ABCDa$$$$$56
• Output: valid
• 
  
• Input: 12345abcd111
• Output: invalid

• Input: 2w3E*
• Output: invalid

Program:

def main():

    password = raw_input("Enter value :")

    digit = 0

    upper = 0

    lower = 0

    special = 0

    flag_len = 0

    for char in password:

        if char.isdigit():

            digit = 1

        if char.isupper():

            upper = 1

        if char.islower():

            lower = 1

        if char == '$' or  char == '#' or char == '@':

            special = 1

    length = len(password)

    if length >= 6 and length <= 12:

        flag_len = 1

    if digit and upper and lower and special and flag_len:

       print "valid"

    else:

       print "invalid"

main()

Output:

python$ python passwordVali.py

Enter value :Velraj

invalid

python$

python$

python$ python passwordVali.py

Enter value :Velraj12#

valid