Add QC method for groupby.sem (modin-project#47) (core)

modin/core/storage_formats/base/query_compiler.py

@@ -2975,6 +2975,28 @@ def groupby_std(
             drop=drop,
         )
 
+    @doc_utils.doc_groupby_method(
+        action="compute standard error", result="standard error", refer_to="sem"
+    )
+    def groupby_sem(
+        self,
+        by,
+        axis,
+        groupby_kwargs,
+        agg_args,
+        agg_kwargs,
+        drop=False,
+    ):
+        return self.groupby_agg(
+            by=by,
+            agg_func="sem",
+            axis=axis,
+            groupby_kwargs=groupby_kwargs,
+            agg_args=agg_args,
+            agg_kwargs=agg_kwargs,
+            drop=drop,
+        )
+
     @doc_utils.doc_groupby_method(
         action="compute numerical rank", result="numerical rank", refer_to="rank"
     )
@@ -4468,7 +4490,9 @@ def str_capitalize(self):
         join : {'left', 'right', 'outer', 'inner'}, default: 'left'""",
     )
     def str_cat(self, others=None, sep=None, na_rep=None, join="left"):
-        return StrDefault.register(pandas.Series.str.cat)(self, others, sep, na_rep, join)
+        return StrDefault.register(pandas.Series.str.cat)(
+            self, others, sep, na_rep, join
+        )
 
     @doc_utils.doc_str_method(
         refer_to="center",
@@ -4543,7 +4567,9 @@ def str_findall(self, pat, flags=0, **kwargs):
         na : object, default: None""",
     )
     def str_fullmatch(self, pat, case=True, flags=0, na=None):
-        return StrDefault.register(pandas.Series.str.fullmatch)(self, pat, case, flags, na)
+        return StrDefault.register(pandas.Series.str.fullmatch)(
+            self, pat, case, flags, na
+        )
 
     @doc_utils.doc_str_method(refer_to="get", params="i : int")
     def str_get(self, i):
@@ -5060,6 +5086,7 @@ def expanding_max(self, fold_axis, expanding_args, *args, **kwargs):
         return RollingDefault.register(pandas.core.window.expanding.Expanding.max)(
             self, expanding_args, *args, **kwargs
         )
+
     def expanding_mean(self, fold_axis, expanding_args, *args, **kwargs):
         return RollingDefault.register(pandas.core.window.expanding.Expanding.mean)(
             self, expanding_args, *args, **kwargs

modin/pandas/groupby.py

@@ -221,7 +221,11 @@ def ffill(self, limit=None):
         return self._default_to_pandas(lambda df: df.ffill(limit=limit))
 
     def sem(self, ddof=1):
-        return self._default_to_pandas(lambda df: df.sem(ddof=ddof))
+        return self._wrap_aggregation(
+            type(self._query_compiler).groupby_sem,
+            agg_kwargs=dict(ddof=ddof),
+            numeric_only=True,
+        )
 
     def value_counts(
         self,
@@ -674,10 +678,13 @@ def do_relabel(obj_to_relabel):
                 kwargs = {}
             func = func_dict
         elif is_list_like(func):
-            return self._default_to_pandas(
-                lambda df, *args, **kwargs: df.aggregate(func, *args, **kwargs),
-                *args,
-                **kwargs,
+            return self._wrap_aggregation(
+                qc_method=type(self._query_compiler).groupby_agg,
+                numeric_only=False,
+                agg_func=func,
+                agg_args=args,
+                agg_kwargs=kwargs,
+                how="axis_wise",
             )
         elif callable(func):
             return self._check_index(