python type annotations
#function expects a string and returns a string
def greeting(name: str) -> str:
return 'Hello ' + name
python type annotations
#function expects a string and returns a string
def greeting(name: str) -> str:
return 'Hello ' + name
python typing list of strings
from typing import List
def my_func(l: List[int]):
pass
python type annotations
# Some basic type annotations
#
# Note that type annotations are not enforced by the interpreter.
# The code
# a: int = 5
# a = "hello"
# is valid Python.
# A built-in library with some extra types that can be used
# for annotations
from typing import Union, Optional, List, Tuple
a: int = 6 # A variable annotated as int
# This denotes a variable that will hold ints and floats over
# the course of its usage.
two_types: Union[int, float] = 5.6
# This variable could hold str or it could be None. This is
# effectively the same as typing opt as Union[str, None].
opt: Optional[str] = None
# This is a function with type annotations; it takes two
# int parameters and returns bool.
def annotated_func(x: int, y: int) -> bool:
return x > y
# You can also annotate a certain data structure and the type of
# data you intend it to contain.
l: List[int] = [1, 2, 3, 4]
t: Tuple[chr] = ('a', 'b', 'c', 'd')
# In Python 3.9+, list[<TYPE>] and tuple[<TYPE>] can be used
# instead. They're aliases for typing.List and typing.Tuple.
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
specify return type python function
def greeting(name: str) -> str:
return 'Hello, {}'.format(name)
python type annotations
# This example illustrates both parameter and return type annotation
# Collection annotations are also supported
from typing import List
def greeting(names: List[str]) -> str:
return 'Hello, ' + names[0] ' and ' + names[1]
Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us