python union type code example

Example 1: python typing list of strings

from typing import List

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

Example 2: typing generator python

# Iterator
def infinite_stream(start: int) -> Iterator[int]:
    while True:
        yield start
        start += 1

# Generator        
def infinite_stream(start: int) -> Generator[int, None, None]:
    while True:
        yield start
        start += 1

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: type declaration python

def greeting(name: str) -> str:
    return 'Hello ' + name

Example 5: .union in python

set1 = {2, 4, 5, 6}  
set2 = {4, 6, 7, 8}  
set3 = {7, 8, 9, 10} 
  
# union of two sets 
print("set1 U set2 : ", set1.union(set2)) 
  
# union of three sets 
print("set1 U set2 U set3 :", set1.union(set2, set3))