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Validate Password Strength in Python

Check if a password is strong based on length and character type rules.

IntermediateConditional ProgramsExample 19 of 20
validate-password-strength.py
1# Program to validate password strength
2

3import re
4

5password = input("Enter a password: ")
6

7length_ok = len(password) >= 8
8has_upper = re.search(r"[A-Z]", password) is not None
9has_lower = re.search(r"[a-z]", password) is not None
10has_digit = re.search(r"[0-9]", password) is not None
11has_special = re.search(r"[^A-Za-z0-9]", password) is not None
12

13if length_ok and has_upper and has_lower and has_digit and has_special:
14    print("Strong password")
15else:
16    print("Weak password")

Output

Enter a password: Abc@1234
Strong password

What's going on

Abc@1234 passes: length 8, upper, lower, digit, symbol. abc123 fails. The regexes are just "is this character class in the string". Skip the length check and "A@1" looks strong.

After this program

If the idea is still fuzzy, read Day 8: Conditional Statements in the Python course. For a short check, try the Python quiz (300 questions). Stay with all 20 conditional programs, or see every topic on Python exercises.

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