PERF: PeriodEngine.get_loc accept narrow data type (#29234)

Author: proost

doc/source/whatsnew/v1.1.0.rst

@@ -40,7 +40,7 @@ Deprecations
 Performance improvements
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
--
+- Performance improvement in :meth:`PeriodIndex.get_loc` using input from user  (:issue:`29038`)
 -
 
 .. ---------------------------------------------------------------------------

pandas/core/indexes/period.py

@@ -598,11 +598,9 @@ def get_loc(self, key, method=None, tolerance=None):
         TypeError
             If key is listlike or otherwise not hashable.
         """
-
         if isinstance(key, str):
             try:
-                asdt, parsed, reso = parse_time_string(key, self.freq)
-                key = asdt
+                key, parsed, reso = parse_time_string(key, self.freq)
             except DateParseError:
                 # A string with invalid format
                 raise KeyError(f"Cannot interpret '{key}' as period")
@@ -613,25 +611,21 @@ def get_loc(self, key, method=None, tolerance=None):
 
         try:
             key = Period(key, freq=self.freq)
+            ordinal = key.ordinal if key is not NaT else key.value
         except ValueError:
             # we cannot construct the Period
             # as we have an invalid type
             if is_list_like(key):
                 raise TypeError(f"'{key}' is an invalid key")
             raise KeyError(key)
 
-        ordinal = key.ordinal if key is not NaT else key.value
+        if tolerance is not None:
+            tolerance = self._convert_tolerance(tolerance, np.asarray(key))
+
         try:
-            return self._engine.get_loc(ordinal)
+            return self._int64index.get_loc(ordinal, method, tolerance)
         except KeyError:
-
-            try:
-                if tolerance is not None:
-                    tolerance = self._convert_tolerance(tolerance, np.asarray(key))
-                return self._int64index.get_loc(ordinal, method, tolerance)
-
-            except KeyError:
-                raise KeyError(key)
+            raise KeyError(key)
 
     def _maybe_cast_slice_bound(self, label, side, kind):
         """

pandas/tests/indexes/common.py

@@ -340,7 +340,7 @@ def test_memory_usage(self, indices):
         # RangeIndex, IntervalIndex
         # don't have engines
         if not isinstance(indices, (RangeIndex, IntervalIndex)):
-            assert result2 > result
+            assert result2 >= result
 
         if indices.inferred_type == "object":
             assert result3 > result2