Python type hints were introduced in Python 3.5 to provide optional static typing for functions and variables through annotations without runtime enforcement. Type aliases allow creating custom types through aliasing existing types and are useful for linting but do not check types at runtime, instead relying on linters to validate correct usage based on type hints. Type hints improve code clarity, readability, testability, and help prevent bugs.

1. Python (3.5+) Type Hints
Using Type Aliases

2. What Are Python Type Hints?
● New in 3.5 (provisional)
● PEP484
● Optional (not enforced at runtime)
○ Linter use recommended instead
● Function annotations
● Type Aliases, NewType, Callable, Generics ...

3. Type Alias

4. Type Alias Linting

5. Type Alias At Runtime

6. Type Alias

7. Type Alias At Runtime

8. Type Alias

9. Type Alias

10. Type Alias (Any type, implicit)

11. Type Alias (Any type, implicit)

12. Type Hints Advantages
● Clarifies, “enforces” intent
● Improves readability
○ Simplifies type signatures
● Improves testability
● May prevent bugs

13. Type Hints Disadvantages
● Lose dynamic typing flexibility
● Syntax complexity