def test(a: int, b: str) -> str:
  print(a, b)
  return 200


if __name__ == '__main__':
  test('test', 'abc')

from typing import List
Vector = List[float]


def scale(scalar: float, vector: Vector) -> Vector:
  return [scalar * num for num in vector]


# type checks; a list of floats qualifies as a Vector.
new_vector = scale(2.0, [1.0, -4.2, 5.4])
print(new_vector)

from typing import Dict, Tuple, Sequence

ConnectionOptions = Dict[str, str]
Address = Tuple[str, int]
Server = Tuple[Address, ConnectionOptions]


def broadcast_message(message: str, servers: Sequence[Server]) -> None:
  print(message)
  print(servers)

# The static type checker will treat the previous type signature as
# being exactly equivalent to this one.


if __name__ == '__main__':
  broadcast_message('OK', [(('127.0.0.1', 8080), {"method": "GET"})])

from typing import NamedTuple


class Employee(NamedTuple):
  name: str
  id: int = 3


employee = Employee('Guido')
# assert employee.id == 3  # 當(dāng)類型一致時(shí)，不會(huì)輸出內(nèi)容，反之報(bào)錯(cuò)
assert employee.id == '3'  # 當(dāng)類型一致時(shí)，不會(huì)輸出內(nèi)容，反之報(bào)錯(cuò)
# AssertionError

from typing import List

def odd_numbers(numbers: List) -> List:
  odd: List[int] = []
  for number in numbers:
    if number % 2:
      odd.append(number)

  return odd

if __name__ == '__main__':
  numbers = list(range(10))
  print(odd_numbers(numbers))

pip install mypy

from typing import List


def odd_numbers(numbers: List) -> List:
  odd: List[int] = []
  for number in numbers:
    if number % 2:
      odd.append(number)

  odd.append('foo')

  return odd


if __name__ == '__main__':
  numbers = list(range(10))
  print(odd_numbers(numbers))

C:\Users\Sunny_Future\AppData\Roaming\Python\Python36\Scripts\mypy.exe tests.py

from typing import Sequence, TypeVar, Union

T = TypeVar('T')   # Declare type variable


def first(l: Sequence[T]) -> T:  # Generic function
  return l[0]


T = TypeVar('T')       # Can be anything
A = TypeVar('A', str, bytes) # Must be str or bytes
A = Union[str, None]     # Must be str or None

# Python 3.6
odd: List[int] = []

# Python 3.5
odd = [] # type: List[int]

from typing import List


def test(b: List[int]) -> str:
  print(b)
  return 'test'


if __name__ == '__main__':
  test([1, 'a'])

# py2 引用
from__future__import annotations

class Starship:
  captain: str = 'Picard'
  damage: int
  stats: ClassVar[Dict[str, int]] = {}

  def __init__(self, damage: int, captain: str = None):
    self.damage = damage
    if captain:
      self.captain = captain # Else keep the default

  def hit(self):
    Starship.stats['hits'] = Starship.stats.get('hits', 0) + 1

enterprise_d = Starship(3000)
enterprise_d.stats = {} # Flagged as error by a type checker
Starship.stats = {} # This is OK

from typing import Dict
class Player:
  ...
players: Dict[str, Player]
__points: int

print(__annotations__)
# prints: {'players': typing.Dict[str, __main__.Player],
#     '_Player__points': <class 'int'>}

class C:
  __annotations__ = 42
  x: int = 5 # raises TypeError