TST: test custom _formatter for ExtensionArray

Author: jorisvandenbossche

pandas/tests/extension/decimal/array.py

@@ -137,6 +137,11 @@ def isna(self):
     def _na_value(self):
         return decimal.Decimal('NaN')
 
+    def _formatter(self, boxed=False):
+        if boxed:
+            return "Decimal: {0}".format
+        return repr
+
     @classmethod
     def _concat_same_type(cls, to_concat):
         return cls(np.concatenate([x._data for x in to_concat]))

pandas/tests/extension/decimal/test_decimal.py

@@ -200,7 +200,13 @@ class TestSetitem(BaseDecimal, base.BaseSetitemTests):
 
 
 class TestPrinting(BaseDecimal, base.BasePrintingTests):
-    pass
+
+    def test_series_repr(self, data):
+        # Overriding this base test to explicitly test that
+        # the custom _formatter is used
+        ser = pd.Series(data)
+        assert data.dtype.name in repr(ser)
+        assert "Decimal: " in repr(ser)
 
 
 # TODO(extension)