Level 6Exercise #140

Redact phone numbers

Replace 10-digit phone numbers, allowing spaces or hyphens, with [REDACTED].

What you’ll practice

This Level 6 exercise focuses on re.sub in the Professional curriculum. Solve the challenge prompt above using clear, idiomatic Python and the relevant language or standard-library tools.

Relevant Python reference: re — Regular expression operations.

Sample Test Cases

Example #1

Input:redact_phones('Call 555-123-4567')

Output:'Call [REDACTED]'

Reference Solution

Reveal Reference Solution

def redact_phones(text: str) -> str:
    import re
    return re.sub(r'\b\d{3}[- ]?\d{3}[- ]?\d{4}\b', '[REDACTED]', text)

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Redact phone numbers

What you’ll practice

Sample Test Cases

Further Reading

Reference Solution