annotated_type.py

from typing import Annotated
from typing_extensions import Annotated

# Define an annotated type with metadata
Age = Annotated[int, "Must be a non-negative integer"]

def check_age(age: Age):
    if age < 0:
        raise ValueError("Age must be a non-negative integer")
    print(f"Age is valid: {age}")

# Usage examples
try:
    check_age(25)  # Valid
    check_age(-5)  # Invalid, will raise ValueError
except ValueError as e:
    print(e)