TYP: Index get_indexer_foo methods (pandas-dev#31137)

Author: jbrockmendel

pandas/_libs/index.pyx

@@ -213,7 +213,8 @@ cdef class IndexEngine:
         return self.monotonic_dec == 1
 
     cdef inline _do_monotonic_check(self):
-        cdef object is_unique
+        cdef:
+            bint is_unique
         try:
             values = self._get_index_values()
             self.monotonic_inc, self.monotonic_dec, is_unique = \
@@ -236,10 +237,10 @@ cdef class IndexEngine:
     cdef _call_monotonic(self, values):
         return algos.is_monotonic(values, timelike=False)
 
-    def get_backfill_indexer(self, other, limit=None):
+    def get_backfill_indexer(self, other: np.ndarray, limit=None) -> np.ndarray:
         return algos.backfill(self._get_index_values(), other, limit=limit)
 
-    def get_pad_indexer(self, other, limit=None):
+    def get_pad_indexer(self, other: np.ndarray, limit=None) -> np.ndarray:
         return algos.pad(self._get_index_values(), other, limit=limit)
 
     cdef _make_hash_table(self, Py_ssize_t n):
@@ -477,13 +478,13 @@ cdef class DatetimeEngine(Int64Engine):
         values = np.asarray(values).view('i8')
         return self.mapping.lookup(values)
 
-    def get_pad_indexer(self, other, limit=None):
+    def get_pad_indexer(self, other: np.ndarray, limit=None) -> np.ndarray:
         if other.dtype != self._get_box_dtype():
             return np.repeat(-1, len(other)).astype('i4')
         other = np.asarray(other).view('i8')
         return algos.pad(self._get_index_values(), other, limit=limit)
 
-    def get_backfill_indexer(self, other, limit=None):
+    def get_backfill_indexer(self, other: np.ndarray, limit=None) -> np.ndarray:
         if other.dtype != self._get_box_dtype():
             return np.repeat(-1, len(other)).astype('i4')
         other = np.asarray(other).view('i8')
@@ -506,16 +507,13 @@ cdef class PeriodEngine(Int64Engine):
     cdef _get_index_values(self):
         return super(PeriodEngine, self).vgetter().view("i8")
 
-    cdef void _call_map_locations(self, values):
-        # super(...) pattern doesn't seem to work with `cdef`
-        Int64Engine._call_map_locations(self, values.view('i8'))
-
     cdef _call_monotonic(self, values):
         # super(...) pattern doesn't seem to work with `cdef`
         return Int64Engine._call_monotonic(self, values.view('i8'))
 
     def get_indexer(self, values):
-        cdef ndarray[int64_t, ndim=1] ordinals
+        cdef:
+            ndarray[int64_t, ndim=1] ordinals
 
         super(PeriodEngine, self)._ensure_mapping_populated()
 
@@ -524,14 +522,14 @@ cdef class PeriodEngine(Int64Engine):
 
         return self.mapping.lookup(ordinals)
 
-    def get_pad_indexer(self, other, limit=None):
+    def get_pad_indexer(self, other: np.ndarray, limit=None) -> np.ndarray:
         freq = super(PeriodEngine, self).vgetter().freq
         ordinal = periodlib.extract_ordinals(other, freq)
 
         return algos.pad(self._get_index_values(),
                          np.asarray(ordinal), limit=limit)
 
-    def get_backfill_indexer(self, other, limit=None):
+    def get_backfill_indexer(self, other: np.ndarray, limit=None) -> np.ndarray:
         freq = super(PeriodEngine, self).vgetter().freq
         ordinal = periodlib.extract_ordinals(other, freq)
 

pandas/_libs/index_class_helper.pxi.in

@@ -53,10 +53,7 @@ cdef class {{name}}Engine(IndexEngine):
             ndarray[{{ctype}}] values
             int count = 0
 
-        {{if name not in {'Float64', 'Float32'} }}
-        if not util.is_integer_object(val):
-            raise KeyError(val)
-        {{endif}}
+        self._check_type(val)
 
         # A view is needed for some subclasses, such as PeriodEngine:
         values = self._get_index_values().view('{{dtype}}')

pandas/core/indexes/base.py

@@ -96,6 +96,7 @@
     duplicated="np.ndarray",
 )
 _index_shared_docs = dict()
+str_t = str
 
 
 def _make_comparison_op(op, cls):
@@ -2959,7 +2960,9 @@ def get_loc(self, key, method=None, tolerance=None):
         """
 
     @Appender(_index_shared_docs["get_indexer"] % _index_doc_kwargs)
-    def get_indexer(self, target, method=None, limit=None, tolerance=None):
+    def get_indexer(
+        self, target, method=None, limit=None, tolerance=None
+    ) -> np.ndarray:
         method = missing.clean_reindex_fill_method(method)
         target = ensure_index(target)
         if tolerance is not None:
@@ -3016,14 +3019,16 @@ def _convert_tolerance(self, tolerance, target):
             raise ValueError("list-like tolerance size must match target index size")
         return tolerance
 
-    def _get_fill_indexer(self, target, method, limit=None, tolerance=None):
+    def _get_fill_indexer(
+        self, target: "Index", method: str_t, limit=None, tolerance=None
+    ) -> np.ndarray:
         if self.is_monotonic_increasing and target.is_monotonic_increasing:
-            method = (
+            engine_method = (
                 self._engine.get_pad_indexer
                 if method == "pad"
                 else self._engine.get_backfill_indexer
             )
-            indexer = method(target._ndarray_values, limit)
+            indexer = engine_method(target._ndarray_values, limit)
         else:
             indexer = self._get_fill_indexer_searchsorted(target, method, limit)
         if tolerance is not None:
@@ -3032,7 +3037,9 @@ def _get_fill_indexer(self, target, method, limit=None, tolerance=None):
             )
         return indexer
 
-    def _get_fill_indexer_searchsorted(self, target, method, limit=None):
+    def _get_fill_indexer_searchsorted(
+        self, target: "Index", method: str_t, limit=None
+    ) -> np.ndarray:
         """
         Fallback pad/backfill get_indexer that works for monotonic decreasing
         indexes and non-monotonic targets.
@@ -3063,7 +3070,7 @@ def _get_fill_indexer_searchsorted(self, target, method, limit=None):
             indexer[indexer == len(self)] = -1
         return indexer
 
-    def _get_nearest_indexer(self, target, limit, tolerance):
+    def _get_nearest_indexer(self, target: "Index", limit, tolerance) -> np.ndarray:
         """
         Get the indexer for the nearest index labels; requires an index with
         values that can be subtracted from each other (e.g., not strings or
@@ -3086,7 +3093,9 @@ def _get_nearest_indexer(self, target, limit, tolerance):
             indexer = self._filter_indexer_tolerance(target, indexer, tolerance)
         return indexer
 
-    def _filter_indexer_tolerance(self, target, indexer, tolerance):
+    def _filter_indexer_tolerance(
+        self, target: "Index", indexer: np.ndarray, tolerance
+    ) -> np.ndarray:
         distance = abs(self.values[indexer] - target)
         indexer = np.where(distance <= tolerance, indexer, -1)
         return indexer