Use window method in moving window's getitem method

The getitem method in moving window is not working properly. Since its
functionality is already provided by the window method that one can be
called.

Signed-off-by: cwasicki <[email protected]>

Author: cwasicki

src/frequenz/sdk/timeseries/_moving_window.py

@@ -358,30 +358,17 @@ def __getitem__(self, key: SupportsIndex | datetime | slice) -> float | ArrayLik
             A float if the key is a number or a timestamp.
             an numpy array if the key is a slice.
         """
+        if isinstance(key, slice):
+            assert key.step is None or key.step == 1
+            return self.window(key.start, key.stop)
+
         if self._buffer.count_valid() == 0:
             raise IndexError("The buffer is empty.")
-        if isinstance(key, slice):
-            if isinstance(key.start, int) or isinstance(key.stop, int):
-                if key.start is None or key.stop is None:
-                    key = slice(slice(key.start, key.stop).indices(self.count_valid()))
-            elif isinstance(key.start, datetime) or isinstance(key.stop, datetime):
-                if key.start is None:
-                    key = slice(self._buffer.time_bound_oldest, key.stop)
-                if key.stop is None:
-                    key = slice(key.start, self._buffer.time_bound_newest)
-
-            _logger.debug("Returning slice for [%s:%s].", key.start, key.stop)
-
-            # we are doing runtime typechecks since there is no abstract slice type yet
-            # see also (https://peps.python.org/pep-0696)
-            if isinstance(key.start, datetime) and isinstance(key.stop, datetime):
-                return self._buffer.window(key.start, key.stop)
-            if isinstance(key.start, int) and isinstance(key.stop, int):
-                return self._buffer[key]
-        elif isinstance(key, datetime):
+
+        if isinstance(key, datetime):
             _logger.debug("Returning value at time %s ", key)
             return self._buffer[self._buffer.to_internal_index(key)]
-        elif isinstance(key, SupportsIndex):
+        if isinstance(key, SupportsIndex):
             _logger.debug("Returning value at index %s ", key)
             return self._buffer[key]
 

tests/timeseries/test_moving_window.py

@@ -117,6 +117,7 @@ def test_eq(expected: list[float], start: int | None, end: int | None) -> None:
         assert np.allclose(
             window.window(start, end), np.array(expected), equal_nan=True
         )
+        assert np.allclose(window[start:end], np.array(expected), equal_nan=True)
 
     async with window:
         test_eq([], 0, 1)