Avoid pyarrow imports

Author: jbrockmendel

pandas/core/indexes/datetimes.py

@@ -389,11 +389,10 @@ def _is_comparable_dtype(self, dtype: DtypeObj) -> bool:
         """
         if isinstance(dtype, ArrowDtype):
             # GH#62277
-            import pyarrow as pa
+            if dtype.kind != "M":
+                return False
 
             pa_dtype = dtype.pyarrow_dtype
-            if not pa.types.is_timestamp(pa_dtype):
-                return False
             if (pa_dtype.tz is None) ^ (self.tz is None):
                 return False
             return True

pandas/core/indexes/timedeltas.py

@@ -196,9 +196,7 @@ def _is_comparable_dtype(self, dtype: DtypeObj) -> bool:
         Can we compare values of the given dtype to our own?
         """
         if isinstance(dtype, ArrowDtype):
-            import pyarrow as pa
-
-            return pa.types.is_duration(dtype.pyarrow_dtype)
+            return dtype.kind == "m"
         return lib.is_np_dtype(dtype, "m")  # aka self._data._is_recognized_dtype
 
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