Python program to check the validity of a Password?

Here given a password, our task is to check that this Password is valid or not. Here we use re module that provide regular expression and re.search() is used for checking the validation of alphabets, digits or special characters.

Algorithm

Step 1: first we take an alphanumeric string as a password.
Step 2: first check that this string should minimum 8 characters.
Step 3: the alphabets must be between a-z.
Step 4: At least one alphabet should be in Uppercase A-Z.
Step 5: At least 1 number or digit between 0-9.
Step 6: At least 1 character from [_ or @ or $].

Example Code

# Python program to check valid password 
import re 
passw = input("Enter Password ::>")
fl = 0
while True:   
   if (len(passw)<8): 
      fl= -1
      break
   elif not re.search("[a-z]", passw): 
      fl = -1
      break
   elif not re.search("[A-Z]", passw): 
        fl = -1
        break
    elif not re.search("[0-9]", passw): 
      fl = -1
      break
   elif not re.search("[_@$]", passw): 
      fl = -1
      break
   elif re.search("\s", passw): 
      fl = -1
      break
   else: 
      fl = 0
      print(" This Is Valid Password") 
      break
if fl ==-1: 
   print("Not a Valid Password") 

Output

Enter Password ::> vbnA@hj9
This Is Valid Password