Python typing: Difference between revisions
From wikinotes
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= Common Types = | = Common Types = | ||
<blockquote> | <blockquote> | ||
== functions/lambdas == | |||
<blockquote> | |||
<syntaxhighlight lang="python"> | |||
from typing import Callable | |||
def run_callback(cb: Callable[[str, int], Bool]) -> None: | |||
</syntaxhighlight> | |||
</blockquote><!-- functions/lambdas --> | |||
== dates/times == | == dates/times == | ||
<blockquote> | <blockquote> |
Revision as of 15:14, 3 April 2022
Type annotations in python.
Example
from typing import Dict, List, Tuple from typing import Optional, Union class Project: def ex_param_w_return(user: User) -> Bool def ex_type_w_default(active: bool=False) -> None: def ex_no_return() -> None: def ex_generics(data: List[Dict]): def ex_optional() -> Optional[str]: # nullable type def ex_type_or_other_type(id: Union[str, int]) -> None:
Common Types
functions/lambdas
from typing import Callable def run_callback(cb: Callable[[str, int], Bool]) -> None:dates/times
import datetime def foo() -> datetime.datetime: return datetime.datetime.now() def foo() -> datetime.date: return datetime.date.today()open file objects
from typing import IO # either bytes/str def foo() -> IO: return open('foo.txt', 'r') def foo() -> IO[bytes]: return open('foo.txt', 'rb') def foo() -> IO[str]: return open('foo.txt', 'r')context managers
@contextlib.contextmanager def foo() -> Iterator[str]: print('foo') yield 'bar' print('baz')