add helper function

python/pyarrow/array.pxi

@@ -903,12 +903,10 @@ cdef class Array(_PandasConvertible):
                                               self, &out))
         result = pandas_api.series(wrap_array_output(out), name=self._name)
 
-        if isinstance(self.type, TimestampType):
-            tz = self.type.tz
-            if tz is not None:
-                tz = string_to_tzinfo(tz)
-                result = (result.dt.tz_localize('utc')
-                          .dt.tz_convert(tz))
+        if isinstance(self.type, TimestampType) and self.type.tz is not None:
+            from pyarrow.pandas_compat import make_tz_aware
+
+            result = make_tz_aware(result, self.type.tz)
 
         return result
 

python/pyarrow/pandas_compat.py

@@ -1046,3 +1046,17 @@ def _add_any_metadata(table, pandas_metadata):
         return pa.Table.from_arrays(columns, schema=pa.schema(fields))
     else:
         return table
+
+
+# ----------------------------------------------------------------------
+# Helper functions used in lib
+
+
+def make_tz_aware(series, tz):
+    """
+    Make a datetime64 Series timezone-aware for the given tz
+    """
+    tz = pa.lib.string_to_tzinfo(tz)
+    series = (series.dt.tz_localize('utc')
+                    .dt.tz_convert(tz))
+    return series

python/pyarrow/table.pxi

@@ -165,12 +165,10 @@ cdef class ChunkedArray(_PandasConvertible):
 
         result = pandas_api.series(wrap_array_output(out), name=self._name)
 
-        if isinstance(self.type, TimestampType):
-            tz = self.type.tz
-            if tz is not None:
-                tz = string_to_tzinfo(tz)
-                result = (result.dt.tz_localize('utc')
-                          .dt.tz_convert(tz))
+        if isinstance(self.type, TimestampType) and self.type.tz is not None:
+            from pyarrow.pandas_compat import make_tz_aware
+
+            result = make_tz_aware(result, self.type.tz)
 
         return result