The code snippet `parent: int` is a type hint or...

The code snippet parent: int is a type hint or type annotation in Python. It specifies that a variable named parent is expected to be of type int (integer). However, without additional context, it doesn't actually do anything by itself — it's merely a declaration to indicate the expected type of the variable.

For example:

parent: int
parent = 42  # This is valid because 42 is an integer.

In Python, type hints do not enforce the type at runtime (they are checked only by static type checkers like mypy). So, this is used primarily for code clarity, tooling, and documentation purposes.