Email List Without Duplicates | Dataford Interview Questions

Explain how you would return an email list without duplicates?

Implement the function below. Treat emails case-insensitively after trimming surrounding whitespace, preserve the first occurrence's cleaned form, and keep the original order.

Input: a list of strings. Output: a new list containing one cleaned string for each distinct email.

Constraints

0 <= len(emails) <= 10^4
Each email is a string
Email strings may contain leading or trailing whitespace
Duplicate comparison is case-insensitive after trimming
The output preserves first-seen order

Function Signature

def unique_emails(emails):

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