What are type hints in Python and how do I use them?

What are type hints in Python and how do I use them?

Type hints in Python are a way to indicate the expected data types of variables, function parameters, and return values. They help with code readability and can assist tools like linters and IDEs in catching errors.

Can you give me an example of how to use type hints in a function?

Sure! Here's a simple example:

def add_numbers(a: int, b: int) -> int:
    return a + b

In this function, a and b are expected to be integers, and the function returns an integer.

Are type hints mandatory in Python?

No, type hints are optional in Python. You can write Python code without them, but using them can improve code quality and maintainability.

What happens if I use the wrong type with type hints?

If you use the wrong type, Python will not raise an error at runtime since it is dynamically typed. However, tools like mypy can help catch these type mismatches during static analysis.