Level 6Exercise #131

Name a reusable type

Define UserId as int | str and annotate a function that normalizes it to str.

What you’ll practice

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

Relevant Python reference: typing — Support for type hints.

Sample Test Cases

Example #1

Input:normalize_user_id(42)

Output:'42'

Reference Solution

Reveal Reference Solution

def normalize_user_id(value: 'UserId') -> str:
    from typing import TypeAlias
    UserId: TypeAlias = int | str
    return str(value)

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Name a reusable type

What you’ll practice

Sample Test Cases

Further Reading

Reference Solution