short circuit more machinery when one_group

Author: nicolaskruchten

packages/python/plotly/plotly/express/_core.py

@@ -1898,6 +1898,7 @@ def infer_config(args, constructor, trace_patch, layout_patch):
 
     # Create grouped mappings
     grouped_mappings = [make_mapping(args, a) for a in grouped_attrs]
+    grouped_mappings = [x for x in grouped_mappings if x.grouper]
 
     # Create trace specs
     trace_specs = make_trace_spec(args, constructor, attrs, trace_patch)
@@ -1915,15 +1916,18 @@ def get_orderings(args, grouper, grouped):
     of tuples like [("value1", ""), ("value2", "")] where each tuple contains the name
     of a single dimension-group
     """
-
     orders = {} if "category_orders" not in args else args["category_orders"].copy()
+
+    if grouper == [one_group]:
+        sorted_group_names = [("",)]
+        return orders, sorted_group_names
+
     for col in grouper:
-        if col != one_group:
-            uniques = list(args["data_frame"][col].unique())
-            if col not in orders:
-                orders[col] = uniques
-            else:
-                orders[col] = list(OrderedDict.fromkeys(list(orders[col]) + uniques))
+        uniques = list(args["data_frame"][col].unique())
+        if col not in orders:
+            orders[col] = uniques
+        else:
+            orders[col] = list(OrderedDict.fromkeys(list(orders[col]) + uniques))
 
     sorted_group_names = []
     for group_name in grouped.groups:
@@ -1932,11 +1936,10 @@ def get_orderings(args, grouper, grouped):
         sorted_group_names.append(group_name)
 
     for i, col in reversed(list(enumerate(grouper))):
-        if col != one_group:
-            sorted_group_names = sorted(
-                sorted_group_names,
-                key=lambda g: orders[col].index(g[i]) if g[i] in orders[col] else -1,
-            )
+        sorted_group_names = sorted(
+            sorted_group_names,
+            key=lambda g: orders[col].index(g[i]) if g[i] in orders[col] else -1,
+        )
     return orders, sorted_group_names
 
 
@@ -1955,8 +1958,12 @@ def make_figure(args, constructor, trace_patch=None, layout_patch=None):
     trace_specs, grouped_mappings, sizeref, show_colorbar = infer_config(
         args, constructor, trace_patch, layout_patch
     )
-    grouper = [x.grouper or one_group for x in grouped_mappings] or [one_group]
-    grouped = args["data_frame"].groupby(grouper, sort=False)
+    if len(grouped_mappings):
+        grouper = [x.grouper for x in grouped_mappings]
+        grouped = args["data_frame"].groupby(grouper, sort=False)
+    else:
+        grouper = [one_group]
+        grouped = None
 
     orders, sorted_group_names = get_orderings(args, grouper, grouped)
 
@@ -1988,7 +1995,12 @@ def make_figure(args, constructor, trace_patch=None, layout_patch=None):
     trace_name_labels = None
     facet_col_wrap = args.get("facet_col_wrap", 0)
     for group_name in sorted_group_names:
-        group = grouped.get_group(group_name if len(group_name) > 1 else group_name[0])
+        if grouped is not None:
+            group = grouped.get_group(
+                group_name if len(group_name) > 1 else group_name[0]
+            )
+        else:
+            group = args["data_frame"]
         mapping_labels = OrderedDict()
         trace_name_labels = OrderedDict()
         frame_name = ""