Password Rules via Lookaheads

Hard ⏱ 18 min 28% acceptance ★★★★★ 4.6

Write strong(pw) validating in a single regex with lookaheads: at least 8 chars, one lowercase, one uppercase, one digit. Each (?=...) asserts without consuming — the idiomatic multi-rule validator.

Examples

Example 1

Input

strong('Passw0rd')

Output

True

Explanation

All four rules hold.

Example 2

Input

strong('password')

Output

False

Explanation

No uppercase, no digit.

Constraints

One fullmatch pattern with three lookaheads.
No separate any() checks.

Topics

Regular Expressionslookaheads

Companies

OktaAuth0Microsoft

Hints

Hint 1

r'(?=.*[a-z])(?=.*[A-Z])(?=.*\d).{8,}'.

Hint 2

Lookaheads all anchor at position 0.

← Collapse Runs of Whitespace Pull Rupee Amounts from Text →

Loading the Python runtime… Run executes your code and shows printed output; Submit checks your function against this problem's examples.