use dataclass instead of namedtuple

janitor/functions/summarize.py

@@ -137,7 +137,8 @@ def summarize(
                     f"Argument {num} should have a maximum length of 3, "
                     f"instead got {len(arg)}"
                 )
-            _, func, names = SD(*arg)
+            data = SD(*arg)
+            func = data.func
             check(
                 f"The function (position 1 in the tuple) for argument {num} ",
                 func,
@@ -151,7 +152,7 @@ def summarize(
                         funcn,
                         [str, callable],
                     )
-
+            names = data.names_glue
             if names:
                 check(
                     f"The names (position 2 in the tuple) for argument {num} ",
@@ -190,9 +191,10 @@ def summarize(
                     aggs[col] = outcome
 
         else:
-            columns, func, names = SD(*arg)
-            columns = _select_index([columns], df, axis="columns")
+            data = SD(*arg)
+            columns = _select_index([data.columns], df, axis="columns")
             columns = df.columns[columns]
+            func = data.func
             if not isinstance(func, (list, tuple)):
                 func = [func]
             func_names = [
@@ -220,6 +222,7 @@ def summarize(
                 func_names = func_list
             counts = None
             func_names = tuple(zip(func_names, func))
+            names = data.names_glue
             for col in columns:
                 if by_is_true:
                     val = grp[col]

janitor/functions/utils.py

@@ -14,7 +14,6 @@
     Union,
     Callable,
     Any,
-    NamedTuple,
 )
 from pandas.core.dtypes.generic import ABCPandasArray, ABCExtensionArray
 from pandas.core.common import is_bool_indexer
@@ -615,7 +614,8 @@ def _convert_to_numpy_array(
     return left, right
 
 
-class SD(NamedTuple):
+@dataclass()
+class SD:
     """
     Subset of Data.
     Used in `mutate` and `summarize`