Make smart futures avoid polling.

[python_utils.git] / input_utils.py

diff --git a/input_utils.py b/input_utils.py
index b19bfe16726dd5995a9d8db52cc7be49b67c8201..a989b2d6fe3db428d25a2de5b8baf6baef3c8734 100644 (file)
--- a/input_utils.py
+++ b/input_utils.py
@@ -2,11 +2,14 @@
 
 """Utilities related to user input."""
 
-import readchar  # type: ignore
 import signal
 import sys
 from typing import List
 
+import readchar  # type: ignore
+
+import exceptions
+
 
 def single_keystroke_response(
     valid_responses: List[str],
@@ -15,11 +18,10 @@ def single_keystroke_response(
     default_response: str = None,
     timeout_seconds: int = None,
 ) -> str:
-    class TimeoutError(Exception):
-        pass
+    """Get a single keystroke response to a prompt."""
 
     def _handle_timeout(signum, frame) -> None:
-        raise TimeoutError()
+        raise exceptions.TimeoutError()
 
     def _single_keystroke_response_internal(
         valid_responses: List[str], timeout_seconds=None
@@ -48,7 +50,7 @@ def single_keystroke_response(
         response = _single_keystroke_response_internal(
             valid_responses, timeout_seconds
         )
-    except TimeoutError:
+    except exceptions.TimeoutError:
         if default_response is not None:
             response = default_response
     if prompt is not None:
@@ -57,12 +59,16 @@ def single_keystroke_response(
 
 
 def yn_response(prompt: str = None, *, timeout_seconds=None) -> str:
+    """Get a Y/N response to a prompt."""
+
     return single_keystroke_response(
         ["y", "n", "Y", "N"], prompt=prompt, timeout_seconds=timeout_seconds
     ).lower()
 
 
 def keystroke_helper() -> None:
+    """Misc util to watch keystrokes and report what they were."""
+
     print("Watching for keystrokes; ^C to quit.")
     while True:
         key = readchar.readkey()