Program to check whether given password meets criteria or not in Python

Suppose we have a string s, representing a password, we have to check the password criteria. There are few rules, that we have to follow −

• Password length will be At least 8 characters and at most 20 characters long.
• Password contains at least one digit
• Password contains at least one lowercase character and one uppercase character
• Password contains at least one special character like !"#$%&\'()*+,-./:;<=>?@[\]^_`{|}~
• Password does not contain any other character like tabs or new lines.

So, if the input is like "@bCd12#4", then the output will be True.

To solve this, we will follow these steps −

• a:= 0, b:= 0, c:= 0, d:= 0
• if size of password < 8 or size of password > 20, then
  • return False
• for each character i in password, do
  • if i is uppercase letter, then
    • a := a + 1
  • otherwise when i is lowercase letter, then
    • b := b + 1
  • otherwise when i in these set of special characters '"!"#^modAND\'() *+,- ./:;<=>?@[\]XOR_`{OR}~"', then
    • c := c + 1
  • otherwise when i is a digit, then
    • d := d + 1
• if a>=1 and b>=1 and c>=1 and d>=1 and a+b+c+d is same as size of the password , then
  • return True
• otherwise,
  • return False

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:
   def solve(self, password):
      a=0
      b=0
      c=0
      d=0
      if len(password)<8 or len(password)>20:
         return False
      for i in password:
         if i.isupper():
            a+=1
         elif i.islower():
            b+=1
         elif i in '"!"#$%&\'()*+,-./:;<=>?@[\]^_`{|}~"':
            c+=1
         elif i.isdigit():
            d+=1
      if a>=1 and b>=1 and c>=1 and d>=1 and
         a+b+c+d==len(password):
      return True
      else:
         return False
s = "@bCd12#4"
ob = Solution()
print(ob.solve(s))

Input

"@bCd12#4"

Output

True