apply black and isort (#4287)

* apply black and isort

* move some type ignores

stdlib/2and3/readline.pyi

@@ -1,36 +1,32 @@
 # Stubs for readline
 
-from typing import Callable, Optional, Sequence
 import sys
+from typing import Callable, Optional, Sequence
 
 _CompleterT = Optional[Callable[[str, int], Optional[str]]]
 _CompDispT = Optional[Callable[[str, Sequence[str], int], None]]
 
-
 def parse_and_bind(string: str) -> None: ...
 def read_init_file(filename: str = ...) -> None: ...
-
 def get_line_buffer() -> str: ...
 def insert_text(string: str) -> None: ...
 def redisplay() -> None: ...
-
 def read_history_file(filename: str = ...) -> None: ...
 def write_history_file(filename: str = ...) -> None: ...
+
 if sys.version_info >= (3, 5):
     def append_history_file(nelements: int, filename: str = ...) -> None: ...
+
 def get_history_length() -> int: ...
 def set_history_length(length: int) -> None: ...
-
 def clear_history() -> None: ...
 def get_current_history_length() -> int: ...
 def get_history_item(index: int) -> str: ...
 def remove_history_item(pos: int) -> None: ...
 def replace_history_item(pos: int, line: str) -> None: ...
 def add_history(string: str) -> None: ...
-
 def set_startup_hook(function: Optional[Callable[[], None]] = ...) -> None: ...
 def set_pre_input_hook(function: Optional[Callable[[], None]] = ...) -> None: ...
-
 def set_completer(function: _CompleterT = ...) -> None: ...
 def get_completer() -> _CompleterT: ...
 def get_completion_type() -> int: ...