question 463 Secure Python · easy

Read the five-digit ZIP from a postcode field

The checkout form accepts a US postcode typed by the customer. The shipping provider's API takes only the five-digit ZIP. Accept the two US formats exactly, return the five-digit part, and return None for anything else, so a malformed value never reaches the API.

Functionzip5(text)

Acceptsfive ASCII digits (02139), or five digits, a hyphen and four digits (02139-4307)

Returnsthe five-digit ZIP as text ("02139" for both examples); None when spaces, letters, other digit scripts or anything extra make the text invalid

Examples

callzip5('02139')returns'02139'

callzip5('02139-4307')returns'02139'

callzip5('2139')returnsNone

callzip5('02139-43')returnsNone