COMPAT: frame round error msg for py310 (#41301)

Author: fangchenli

pandas/core/frame.py

@@ -9207,9 +9207,12 @@ def _series_round(s, decimals):
         nv.validate_round(args, kwargs)
 
         if isinstance(decimals, (dict, Series)):
-            if isinstance(decimals, Series):
-                if not decimals.index.is_unique:
-                    raise ValueError("Index of decimals must be unique")
+            if isinstance(decimals, Series) and not decimals.index.is_unique:
+                raise ValueError("Index of decimals must be unique")
+            if is_dict_like(decimals) and not all(
+                is_integer(value) for _, value in decimals.items()
+            ):
+                raise TypeError("Values in decimals must be integers")
             new_cols = list(_dict_round(self, decimals))
         elif is_integer(decimals):
             # Dispatch to Series.round

pandas/tests/frame/methods/test_round.py

@@ -62,13 +62,12 @@ def test_round(self):
 
         # float input to `decimals`
         non_int_round_dict = {"col1": 1, "col2": 0.5}
-        msg = "integer argument expected, got float"
+        msg = "Values in decimals must be integers"
         with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_dict)
 
         # String input
         non_int_round_dict = {"col1": 1, "col2": "foo"}
-        msg = r"an integer is required \(got type str\)"
         with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_dict)
 
@@ -78,7 +77,6 @@ def test_round(self):
 
         # List input
         non_int_round_dict = {"col1": 1, "col2": [1, 2]}
-        msg = r"an integer is required \(got type list\)"
         with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_dict)
 
@@ -106,7 +104,6 @@ def test_round(self):
         # nan in Series round
         nan_round_Series = Series({"col1": np.nan, "col2": 1})
 
-        msg = "integer argument expected, got float"
         with pytest.raises(TypeError, match=msg):
             df.round(nan_round_Series)