BUG: PeriodEngine doesn't work (#29038)

Author: proost

pandas/core/indexes/period.py

@@ -642,36 +642,30 @@ def get_loc(self, key, method=None, tolerance=None):
         -------
         loc : int
         """
-        try:
-            return self._engine.get_loc(key)
-        except KeyError:
-            if is_integer(key):
-                raise
-
-            try:
-                asdt, parsed, reso = parse_time_string(key, self.freq)
-                key = asdt
-            except TypeError:
-                pass
-            except DateParseError:
-                # A string with invalid format
-                raise KeyError(f"Cannot interpret '{key}' as period")
+        if is_integer(key) or (is_float(key) and not isna(key)):
+            ordinal = key
+        else:
+            if isinstance(key, str):
+                try:
+                    key, parsed, reso = parse_time_string(key, self.freq)
+                except DateParseError:
+                    # A string with invalid format
+                    raise KeyError(f"Cannot interpret '{key}' as period")
 
             try:
                 key = Period(key, freq=self.freq)
+                ordinal = iNaT if key is NaT else key.ordinal
             except ValueError:
-                # we cannot construct the Period
-                # as we have an invalid type
-                raise KeyError(key)
+                # we cannot construct the Period as we have an invalid type
+                raise TypeError(f"'{key}' is an invalid key")
 
-            try:
-                ordinal = iNaT if key is NaT else key.ordinal
-                if tolerance is not None:
-                    tolerance = self._convert_tolerance(tolerance, np.asarray(key))
-                return self._int64index.get_loc(ordinal, method, tolerance)
+        if tolerance is not None:
+            tolerance = self._convert_tolerance(tolerance, np.asarray(key))
 
-            except KeyError:
-                raise KeyError(key)
+        try:
+            return self._int64index.get_loc(ordinal, method, tolerance)
+        except KeyError:
+            raise KeyError(key)
 
     def _maybe_cast_slice_bound(self, label, side, kind):
         """

pandas/tests/indexes/common.py

@@ -339,7 +339,7 @@ def test_memory_usage(self, indices):
 
         # RangeIndex, IntervalIndex
         # don't have engines
-        if not isinstance(indices, (RangeIndex, IntervalIndex)):
+        if not isinstance(indices, (RangeIndex, IntervalIndex, PeriodIndex)):
             assert result2 > result
 
         if indices.inferred_type == "object":