python static typing code example

Example 1: static typing in python

# Python will always remain a dynamically typed language.
# However, PEP 484 introduced type hints, which make it possible to
# also do static type checking of Python code.

name: str = 'Bob'
age: int = 32
rating: float = 7.9
is_premium: bool = True

Example 2: python typing list of strings

from typing import List

def my_func(l: List[int]):
    pass

Example 3: python type hint list

# For collections, the name of the type is capitalized, and the
# name of the type inside the collection is in brackets
x: List[int] = [1]
x: Set[int] = {6, 7}
  
# For simple built-in types, just use the name of the type
x: int = 1
x: float = 1.0
x: bool = True
x: str = "test"
x: bytes = b"test"

Example 4: python optional type annotation

from custom_module import SomeClass
from typing import Optional

class SubClass:
    a_reference: Optional[SomeClass] # Provides info that a_reference may be 'None'.

    def __init__(self):
        self.a_reference = None

Tags:

Misc Example

Related