Stop: In the above example, you can find the outcomes of the last four commands are all 312. What's the difference between them? Why do we need different ways to find the same outcome? Try ...

The syntax of Python type hints. ... Also note that Optional can be hinted as a Union with None; for example, int|None instead of Optional[int].

It allows one of a number of possible actions to be taken based on the value of a given variable or expression. While Python has lacked a native syntax for pattern matching, ...