"""A simple stopwatch decorator / context for timing things."""
+import contextlib
import time
-from typing import Callable, Optional
+from typing import Callable, Literal
-class Timer(object):
+class Timer(contextlib.AbstractContextManager):
"""
A stopwatch to time how long something takes (walltime).
self.end = 0.0
return lambda: self.end - self.start
- def __exit__(self, *args) -> Optional[bool]:
+ def __exit__(self, *args) -> Literal[False]:
self.end = time.perf_counter()
- return None # don't suppress exceptions
+ return False