apply black and isort (#4287)

* apply black and isort

* move some type ignores

stdlib/2and3/netrc.pyi

@@ -1,19 +1,15 @@
 from typing import AnyStr, Dict, List, Optional, Tuple, overload
 
-
 class NetrcParseError(Exception):
     filename: Optional[str]
     lineno: Optional[int]
     msg: str
 
-
 # (login, account, password) tuple
 _NetrcTuple = Tuple[str, Optional[str], Optional[str]]
 
-
 class netrc:
     hosts: Dict[str, _NetrcTuple]
     macros: Dict[str, List[str]]
-
     def __init__(self, file: str = ...) -> None: ...
     def authenticators(self, host: str) -> Optional[_NetrcTuple]: ...