Validate dict schema at pipeline boundary in Python

from typing import Any, TypedDict


class Person(TypedDict):
    name: str
    age: int
    email: str


def validate_person(data: dict[str, Any]) -> Person:
    errors: list[str] = []

    if not isinstance(data.get("name"), str) or not data["name"].strip():
        errors.append("name must be a non-empty string")
    if not isinstance(data.get("age"), int) or data["age"] < 0:
        errors.append("age must be a non-negative integer")
    if not isinstance(data.get("email"), str) or "@" not in data["email"]:
        errors.append("email must be a valid string containing '@'")

    if errors:
        raise ValueError(f"Validation failed: {'; '.join(errors)}")

    return {
        "name": data["name"].strip(),
        "age": data["age"],
        "email": data["email"].strip(),
    }


if __name__ == "__main__":
    valid_input = {"name": "  Alice  ", "age": 30, "email": "alice@example.com"}
    invalid_input = {"name": "", "age": -5, "email": "not-an-email"}

    print("Valid input:", validate_person(valid_input))

    try:
        validate_person(invalid_input)
    except ValueError as exc:
        print("Invalid input error:", exc)