Python Cyber Security - Check password strength and get suggestions

Last update on April 24 2025 12:42:21 (UTC/GMT +8 hours)

7. Password Strength Meter

Write a Python program that creates a password strength meter. The program should prompt the user to enter a password and check its strength based on criteria such as length, complexity, and randomness. Afterwards, the program should provide suggestions for improving the password's strength.

The highest strength password that meets the criteria specified in the program will receive a score of 5.

(e.g. at least 8 characters, contains both uppercase and lowercase letters, and at least one number and one special character).

Sample Solution:

Python Code:

import re

def check_password_strength(password):
    score = 0
    suggestions = []

    # check length
    if len(password) >= 8:
        score += 1
    else:
        suggestions.append("Password should be at least 8 characters long")

    # check for uppercase letter
    if re.search(r"[A-Z]", password):
        score += 1
    else:
        suggestions.append("Password should contain at least one uppercase letter")

    # check for lowercase letter
    if re.search(r"[a-z]", password):
        score += 1
    else:
        suggestions.append("Password should contain at least one lowercase letter")

    # check for numeric digit
    if re.search(r"\d", password):
        score += 1
    else:
        suggestions.append("Password should contain at least one numeric digit")

    # check for special character
    if re.search(r"[!@#$%^&*(),.?\":{}|<>]", password):
        score += 1
    else:
        suggestions.append("Password should contain at least one special character (!@#$%^&*(),.?\":{}|<>)")

    return score, suggestions
password = input("Input a password: ")
print(check_password_strength(password))

Sample Output:

Input a password: Akoiuw3^*(!@
(5, [])

Input a password: ABH4@LLO
(4, ['Password should contain at least one lowercase letter'])

Input a password: Ohuyt1234
(4, ['Password should contain at least one special character (!@#$%^&*(),.?":{}|<>)'])

Input a password: Aqwjuir
(2, ['Password should be at least 8 characters long', 'Password should contain at least one numeric digit', 'Password should contain at least one special character (!@#$%^&*(),.?":{}|<>)'])

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program that prompts the user for a password and then rates its strength based on length, complexity, and randomness, printing detailed feedback.
Write a Python function that computes a strength score for a password and returns a grade (e.g., Weak, Moderate, Strong), then tests it with sample inputs.
Write a Python script to implement a password strength meter that outputs a graphical bar (using characters) representing the password strength.
Write a Python program to analyze a password's composition and suggest improvements (such as adding digits or special characters) if it is weak.

Go to:

Previous: Check if passwords in a list have been leaked in data breaches.
Next: Generate password from a dictionary file.

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.