Type Hints in Python

 Type hints in Python are an excellent tool for improving code quality and maintainability, especially in larger projects. 

from typing import Optional

class TreeNode:

    def __init__(self, value: int) -> None:

        self.value = value

        self.left: Optional['TreeNode'] = None

        self.right: Optional['TreeNode'] = None

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class LinkedListNode:

    def __init__(self, value: int, next_node: 'LinkedListNode' = None) -> None:

        self.value = value

        self.next = next_node

#clcoding.com

from typing import Optional

class TreeNode:

    def __init__(self, value: int) -> None:

        self.value = value

        self.left: Optional['TreeNode'] = None

        self.right: Optional['TreeNode'] = None

#clcoding.com

from typing import TypeVar

class Animal:

    def speak(self) -> str:

        raise NotImplementedError

class Dog(Animal):

    def speak(self) -> str:

        return "Woof!"

T = TypeVar('T', bound=Animal)

def make_sound(animal: T) -> str:

    return animal.speak()

#clcoding.com

from typing import Callable

def apply_func(func: Callable[[int, int], int], a: int, b: int) -> int:

    return func(a, b)

#clcoding.com

from typing import Iterable, TypeVar

T = TypeVar('T')

def process_items(items: Iterable[T]) -> None:

    for item in items:

        # Process each item

        pass

#clcoding.com

from typing import TypeVar, Iterable

T = TypeVar('T')

def first_element(items: Iterable[T]) -> T:

    return next(iter(items))

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from typing import List, Tuple

Point = Tuple[int, int]

Polygon = List[Point]

def area(polygon: Polygon) -> float:

    # Calculate area of polygon

    pass

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from typing import Union

def square_root(num: Union[int, float]) -> Union[int, float]:

    return num ** 0.5

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from typing import Optional

def greet(name: Optional[str]) -> str:

    if name:

        return f"Hello, {name}!"

    else:

        return "Hello, anonymous!"

#clcoding.com