Python Type Hints

제 3회 파이썬 격월 세미나에서 발표한 [Python Type Hints] 발표 슬라이드입니다. (https://www.facebook.com/groups/pythonkorea/)

Transcript

1. Python Type Hints presenter: str = "sunghyunzz"
2. PEP 484 - Type Hints • PEP 3107 - Function Annotations
3. PEP 484 - Type Hints • PEP 3107 - Function Annotations • 2014-09-29
4. PEP 484 - Type Hints • PEP 3107 - Function Annotations • 2014-09-29 • Python 3.5
5. def add(a: int, b: int) -> int: return a + b
6. def print_sum(a: int, b: int) -> None: print(a + b)
7. def get_list(a: int, b: int) -> list: return [a, b]
8. def get_list(a: int, b: int) -> list: return [a, b] from typing import List def get_list(a: int, b: int) -> List[int]: return [a, b]
9. def get_list(a: int, b: int) -> List: return ['a', a, 'b', b, 'a + b', a + b]
10. def get_list(a: int, b: int) -> List: return ['a', a, 'b', b, 'a + b', a + b]
11. def get_list(a: int, b: int) -> list: return [a, b] from typing import Any, List def get_list(a: int, b: int) -> List[Any]: return ['a', a, 'b', b, 'a + b', a + b]
12. def func(text: str) -> str: result: int = some_complex_func(text) return str(result)
13. class Person: def __init__(self, name: str) -> None: self.name: str = name self.length_of_name: int = len(name)
14. from typing import List, Union result: List[Union[int, str]] = [1, 'a', 2, 'b']
15. from typing import Optional, Union assert Optional[int] == Union[int, None]
16. from typing import Dict, Set def get_dict(a: int) -> Dict[int, str]: return { a: str(a), a + 1: str(a + 1) } def get_set(a: int) -> Set[int]: return {a, a + 1}
17. from typing import Tuple def get_tuple(a: int, b: int) -> Tuple[int]: return a, b # Expected type 'Tuple[int]', got 'Tuple[int, int]' instead
18. from typing import Tuple def get_tuple(a: int, b: int) -> Tuple[int, int]: return a, b
19. from typing import Tuple def get_tuple() -> Tuple[int, int, int, int, int, int, int, int, int, int]: return 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
20. from typing import Tuple def get_tuple() -> Tuple[int, ...]: return 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
21. from typing import Callable def add_lazy(a: int, b: int): def f() -> int: return a + b return f
22. from typing import Callable def add_lazy(a: int, b: int) -> Callable[[], int]: def f() -> int: return a + b return f
23. from typing import Callable def run(f: Callable[[int, str], int], a: int, b: str) -> int: return f(a, b)
24. def run(f: Callable[..., int], *args) -> int: return f(args)
25. def run(f: Callable[..., int], *args: int) -> int: return f(args)
26. def run( f: Callable[[Dict[str, int]], int], **kwargs: int ) -> int: return f(kwargs)
27. def run( f: Callable[[Dict[str, int]], int], **kwargs: int ) -> int: return f(kwargs)
28. def run( f: Callable[[Dict[str, int]], int], **kwargs: int ) -> int: return f(kwargs)
29. IntReturningFunction = Callable[..., int] def run(f: IntReturningFunction) -> int: return f(1, 2, 3, 4, 5)
30. def fetch(_id: int, category: int) -> Transaction: pass
31. EntityID = int def fetch(_id: EntityID, category: int) -> Transaction: pass
32. class Person: def get_children(self) -> List[Person]: pass
33. class Person: def get_children(self) -> List[Person]: pass NameError: name 'Person' is not defined
34. class Person: def get_children(self) -> List[Person]: pass def get_children(self) -> List['Person']: pass
35. from abc import ABCMeta, abstractmethod from typing import Generic, TypeVar T = TypeVar('T') class Person: pass class Mapper(Generic[T], metaclass=ABCMeta): @classmethod @abstractmethod def from_dict(cls, request: dict) -> T: pass def convert(mapper: Mapper[Person], data: dict) -> Person: return mapper.from_dict(data)
36. from abc import ABCMeta, abstractmethod from typing import Generic, TypeVar T = TypeVar('T') class Person: pass class Mapper(Generic[T], metaclass=ABCMeta): @classmethod @abstractmethod def from_dict(cls, request: dict) -> T: pass def convert(mapper: Mapper[Person], data: dict) -> Person: return mapper.from_dict(data)
37. from abc import ABCMeta, abstractmethod from typing import Generic, TypeVar T = TypeVar('T') class Person: pass class Mapper(Generic[T], metaclass=ABCMeta): @classmethod @abstractmethod def from_dict(cls, request: dict) -> T: pass def convert(mapper: Mapper[Person], data: dict) -> Person: return mapper.from_dict(data)
38. from abc import ABCMeta, abstractmethod from typing import Generic, TypeVar T = TypeVar('T') class Person: pass class Mapper(Generic[T], metaclass=ABCMeta): @classmethod @abstractmethod def from_dict(cls, request: dict) -> T: pass def convert(mapper: Mapper[Person], data: dict) -> Person: return mapper.from_dict(data)
39. from abc import ABCMeta, abstractmethod from typing import Generic, TypeVar T = TypeVar('T') class Person: pass class Mapper(Generic[T], metaclass=ABCMeta): @classmethod @abstractmethod def from_dict(cls, request: dict) -> T: pass def convert(mapper: Mapper[Person], data: dict) -> Person: return mapper.from_dict(data)
40. from abc import ABCMeta, abstractmethod from typing import Generic, TypeVar T = TypeVar('T') class Person: pass class Mapper(Generic[T], metaclass=ABCMeta): @classmethod @abstractmethod def from_dict(cls, request: dict) -> T: pass def convert(mapper: Mapper[Person], data: dict) -> Person: return mapper.from_dict(data)
41. python2 support from typing import List def hello(): # type: () -> None print 'hello' class Example: def method(self, lst, opt=0, *args, **kwargs): # type: (List[str], int, *str, **bool) -> int """Docstring comes after type comment."""
42. # some other package (math.py) def add(a, b): return a + b
43. # stub (math.pyi) def add(a: float, b: float) -> float: …
45. python/typeshed • contains external type annotations for the Python standard library and Python builtins
46. python/typeshed • contains external type annotations for the Python standard library and Python builtins • as well as third party packages.
53. [mypy] disallow_untyped_defs = True strict_optional = True warn_redundant_casts = True
54. :+1: • ޙࢲച੄ ӝמ (ӝઓ੄ docstring convention ؀୓)
55. :+1: • ޙࢲച੄ ӝמ (ӝઓ੄ docstring convention ؀୓) • IDE/ী٣ఠ ఋੑ ୶ۿ ѐࢶ
56. :+1: • ޙࢲച੄ ӝמ (ӝઓ੄ docstring convention ؀୓) • IDE/ী٣ఠ ఋੑ ୶ۿ ѐࢶ • ੿੸ Type Checkerܳ ాೠ पࣻ ߑ૑
57. :-1: • ҃਋ী ٮۄ ࠛ೙ਃೠ ௏٘੄ ୶о
58. :-1: • ҃਋ী ٮۄ ࠛ೙ਃೠ ௏٘੄ ୶о • (ই૒਷) ׮ࣗ ࠗ઒ೠ ఋੑ दझమ
59. “Python is dynamically typed and we like it that way!” - Guido van Rossum
60. ۨ੉פझ౟ীࢲח • ఋੑ ݺदо ௏٘੄ оةࢿਸ ֫ੋ׮Ҋ ޺ਵݴ ೐۽ં౟ ҙܻ ࠺ਊਸ ծ୹ ࣻ ੓׮Ҋ ౸ױೞৈ بੑ೮णפ׮.
61. ۨ੉פझ౟ীࢲח • ఋੑ ݺदо ௏٘੄ оةࢿਸ ֫ੋ׮Ҋ ޺ਵݴ ೐۽ં౟ ҙܻ ࠺ਊਸ ծ୹ ࣻ ੓׮Ҋ ౸ױೞৈ بੑ೮णפ׮. • नӏ ೐۽ં౟ח CI җ੿ীࢲ mypyܳ प೯೤פ׮.
62. ۨ੉פझ౟ীࢲח • ఋੑ ݺदо ௏٘੄ оةࢿਸ ֫ੋ׮Ҋ ޺ਵݴ ೐۽ં౟ ҙܻ ࠺ਊਸ ծ୹ ࣻ ੓׮Ҋ ౸ױೞৈ بੑ೮णפ׮. • नӏ ೐۽ં౟ח CI җ੿ীࢲ mypyܳ प೯೤פ׮. • ఋੑ दझమ੄ ೠ҅۽ ੋ೧ ࠛ೙ਃೠ ௏٘ܳ ੘ࢿ೧ঠ ೡ ٸ ীח @typing.no_type_check
63. ߛ௼࢟۞٘ܳ ݅٘ח ۨ੉פझ౟ীࢲ ੷൞ ৬ ೣԋೡ ࢲߡ ূ૑פয ٜ࠙ਸ ଺Ҋ ੓ णפ׮. Python, aiohttp, django
64. Questions github: sunghyunzz email: me@sunghyunzz.com