What is Type Hinting?

Type hinting is a formal solution to statically indicate the type of a value within your Python code. It was specified in PEP 484 and introduced in Python 3.5.

Credit: RealPython

Basically, It allows you to put the static type into Python code like Java , Typescript , etc.

def add(x):
    return x+1
        
print(add(1))

def add(x:float)->float:
    return x+1

print(add(1))

Pros and Cons

Pros

• IDE can understand your code better.

  class Candy:
      def __init__(self, color) -> None:
          self.color = color
  
  def are_two_candies_same_color(candy1, candy2):
      return candy1.color == candy2.color
      
  red_candy = Candy("red")
  blue_candy = Candy("blue")
  
  print(are_two_candies_same_color(red_candy, blue_candy))
  

  ---

  class Candy:
      color:str
      def __init__(self, color:str) -> None:
          self.color = color
  
  def are_two_candies_same_color(candy1:Candy, candy2:Candy) -> bool:
      return candy1.color == candy2.color
  
  red_candy = Candy("red")
  blue_candy = Candy("blue")
  
  print(are_two_candies_same_color(red_candy,blue_candy))
  

  ---

  

Cons

• Learning curve

PS.

• Actually, Python does not do anything about type checking.

def func(x:str) -> None:
    """
    do something
    """
    print(x)

func(1)




        output:
1

• However, You can install mypy and your IDE will be able to check your type before running the code.