Python
9 Advanced Python Type Hints That Will Improve Your Code Significantly
Elegance, one step further
If you ask which version of Python 3 impressed me most, I would say Python 3.5.
In September 2015, Python 3.5 was released with a new feature called type hints. Since then, Python, as a dynamic typing language, has a way to be type-safe.
After all these years, Python’s type hints are much more comprehensive. It can cover almost all scenarios for type checking in our daily programming.
This article will summarize and explain 9 next-level type hints beyond basic usages, covering the most impressive advanced techniques from Python 3.5 to the latest Python 3.13.
1. TypeVar: Declare Type Variables
As its name implies, a TypeVar is used to define a type variable without any specific type.
It seems unnecessary at first glance. Given that it wouldn’t define a specific type, why bother to use type hints?
Let’s understand it through an example:
from typing import TypeVar, List
T = TypeVar('T')
def get_first(l: List[T]) -> T:
return l[0]
numbers: List[int] = [1, 2, 3]
result: int = get_first(numbers)
result2: str =…
