Merge pull request #3767 from jvdd/one_group_short_circuit

♻️ check for all same groups

Author: nicolaskruchten

Diff for: packages/python/plotly/plotly/express/_core.py

@@ -1904,7 +1904,7 @@ def infer_config(args, constructor, trace_patch, layout_patch):
     return trace_specs, grouped_mappings, sizeref, show_colorbar
 
 
-def get_orderings(args, grouper, grouped):
+def get_orderings(args, grouper, grouped, all_same_group):
     """
     `orders` is the user-supplied ordering with the remaining data-frame-supplied
     ordering appended if the column is used for grouping. It includes anything the user
@@ -1916,10 +1916,17 @@ def get_orderings(args, grouper, grouped):
     of a single dimension-group
     """
     orders = {} if "category_orders" not in args else args["category_orders"].copy()
+    sorted_group_names = []
 
-    if _all_one_group(grouper):
-        sorted_group_names = [("",) * len(grouper)]
-        return orders, sorted_group_names
+    if all_same_group:
+        for col in grouper:
+            if col != one_group:
+                single_val = args["data_frame"][col].iloc[0]
+                sorted_group_names.append(single_val)
+                orders[col] = [single_val]
+            else:
+                sorted_group_names.append("")
+        return orders, [tuple(sorted_group_names)]
 
     for col in grouper:
         if col != one_group:
@@ -1929,7 +1936,6 @@ def get_orderings(args, grouper, grouped):
             else:
                 orders[col] = list(OrderedDict.fromkeys(list(orders[col]) + uniques))
 
-    sorted_group_names = []
     for group_name in grouped.groups:
         if len(grouper) == 1:
             group_name = (group_name,)
@@ -1944,10 +1950,12 @@ def get_orderings(args, grouper, grouped):
     return orders, sorted_group_names
 
 
-def _all_one_group(grouper):
-    for g in grouper:
+def _all_same_group(args, grouper):
+    for g in set(grouper):
         if g != one_group:
-            return False
+            arr = args["data_frame"][g].values
+            if not (arr[0] == arr).all(axis=0):
+                return False
     return True
 
 
@@ -1968,10 +1976,11 @@ def make_figure(args, constructor, trace_patch=None, layout_patch=None):
     )
     grouper = [x.grouper or one_group for x in grouped_mappings] or [one_group]
     grouped = None
-    if not _all_one_group(grouper):
+    all_same_group = _all_same_group(args, grouper)
+    if not all_same_group:
         grouped = args["data_frame"].groupby(grouper, sort=False)
 
-    orders, sorted_group_names = get_orderings(args, grouper, grouped)
+    orders, sorted_group_names = get_orderings(args, grouper, grouped, all_same_group)
 
     col_labels = []
     row_labels = []