googleapis · TrevorBergeron · Oct 22, 2025 · Oct 20, 2025 · Oct 22, 2025 · sycai
@@ -177,6 +177,9 @@ def __iter__(self) -> Iterable[Tuple[blocks.Label, df.DataFrame]]:
            filtered_df = df.DataFrame(filtered_block)
            yield group_keys, filtered_df

+    def __len__(self) -> int:
+        return len(self.agg([]))
+
    def size(self) -> typing.Union[df.DataFrame, series.Series]:
        agg_block, _ = self._block.aggregate_size(
            by_column_ids=self._by_col_ids,

@@ -108,6 +108,9 @@ def __iter__(self) -> Iterable[Tuple[blocks.Label, series.Series]]:
            filtered_series.name = self._value_name
            yield group_keys, filtered_series

+    def __len__(self) -> int:
+        return len(self.agg([]))
+
    def all(self) -> series.Series:
        return self._aggregate(agg_ops.all_op)

@@ -275,9 +278,9 @@ def agg(self, func=None) -> typing.Union[df.DataFrame, series.Series]:
        if column_names:
            agg_block = agg_block.with_column_labels(column_names)

-        if len(aggregations) > 1:
-            return df.DataFrame(agg_block)
-        return series.Series(agg_block)
+        if len(aggregations) == 1:
+            return series.Series(agg_block)
+        return df.DataFrame(agg_block)

    aggregate = agg


@@ -61,6 +61,15 @@ def test_dataframe_groupby_head(scalars_df_index, scalars_pandas_df_index):
    pd.testing.assert_frame_equal(pd_result, bf_result, check_dtype=False)


+def test_dataframe_groupby_len(scalars_df_index, scalars_pandas_df_index):
+    col_names = ["int64_too", "float64_col", "int64_col", "bool_col", "string_col"]
+
+    bf_result = len(scalars_df_index[col_names].groupby("bool_col"))
+    pd_result = len(scalars_pandas_df_index[col_names].groupby("bool_col"))
+
+    assert bf_result == pd_result
+
+
 def test_dataframe_groupby_median(scalars_df_index, scalars_pandas_df_index):
    col_names = ["int64_too", "float64_col", "int64_col", "bool_col", "string_col"]
    bf_result = (
@@ -668,6 +677,13 @@ def test_dataframe_groupby_last(
 # ==============


+def test_series_groupby_len(scalars_df_index, scalars_pandas_df_index):
+    bf_result = len(scalars_df_index.groupby("bool_col")["int64_col"])
+    pd_result = len(scalars_pandas_df_index.groupby("bool_col")["int64_col"])
+
+    assert bf_result == pd_result
+
+
 @pytest.mark.parametrize(
    ("agg"),
    [
-Original file line number
+Diff line change
@@ -61,6 +61,15 @@ def test_dataframe_groupby_head(scalars_df_index, scalars_pandas_df_index):
         pd.testing.assert_frame_equal(pd_result, bf_result, check_dtype=False)
+    def test_dataframe_groupby_len(scalars_df_index, scalars_pandas_df_index):
+        col_names = ["int64_too", "float64_col", "int64_col", "bool_col", "string_col"]
+        bf_result = len(scalars_df_index[col_names].groupby("bool_col"))
+        pd_result = len(scalars_pandas_df_index[col_names].groupby("bool_col"))
+        assert bf_result == pd_result
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            sycai
  

      

      

      


        Oct 21, 2025



      
    

  

  
    
      
          
    
  


        
            
  
      
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      style nits: empty spaces between "arrange" "act" "assert" blocks: https://g3doc.corp.google.com/eng/doc/devguide/testing/unit/best-practices.md?cl=head&polyglot=python#structure
    
  
  



    

        
      
  
  
    
  
  
  
    
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            TrevorBergeron
  

      

      

      


        Oct 22, 2025



      
    

  

  
    
      
          
    
  


        
            
  
      
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     def test_dataframe_groupby_median(scalars_df_index, scalars_pandas_df_index):
         col_names = ["int64_too", "float64_col", "int64_col", "bool_col", "string_col"]
         bf_result = (
@@ -668,6 +677,13 @@ def test_dataframe_groupby_last(
     # ==============
+    def test_series_groupby_len(scalars_df_index, scalars_pandas_df_index):
+        bf_result = len(scalars_df_index.groupby("bool_col")["int64_col"])
+        pd_result = len(scalars_pandas_df_index.groupby("bool_col")["int64_col"])
+        assert bf_result == pd_result
     @pytest.mark.parametrize(
         ("agg"),
         [
-          Expand Down