Show one progress bar per chain when sampling

pymc/util.py

@@ -704,28 +704,38 @@ def callbacks(self, task: "Task"):
 
 class ProgressManager:
     def __init__(self, step_method, chains, draws, tune, progressbar, progressbar_theme):
-        mode = "chain"
-        stats = "full"
-
-        if isinstance(progressbar, bool):
-            show_progress = progressbar
-        else:
-            show_progress = True
-
-            if "+" in progressbar:
-                mode, stats = progressbar.split("+")
-            else:
-                mode = progressbar
-                stats = "full"
-
-        if mode not in ["chain", "combined"]:
-            raise ValueError('Invalid mode. Valid values are "chain" and "combined"')
-        if stats not in ["full", "simple"]:
-            raise ValueError('Invalid stats. Valid values are "full" and "simple"')
+        self.combined_progress = False
+        self.full_stats = True
+        show_progress = True
+
+        match progressbar:
+            case True:
+                show_progress = True
+            case False:
+                show_progress = False
+            case "combined":
+                self.combined_progress = True
+            case "chain":
+                self.combined_progress = False
+            case "combined+full":
+                self.combined_progress = True
+                self.full_stats = True
+            case "combined+simple":
+                self.combined_progress = True
+                self.full_stats = False
+            case "chain+full":
+                self.combined_progress = False
+                self.full_stats = True
+            case "chain+simple":
+                self.combined_progress = False
+                self.full_stats = False
+            case _:
+                raise ValueError(
+                    "Invalid value for `progressbar`. Valid values are True (default), False (no progress bar), "
+                    "or one of 'combined', 'chain', 'combined+full', 'combined+simple', 'chain+full', 'chain+simple'."
+                )
 
         progress_columns, progress_stats = step_method._progressbar_config(chains)
-        self.combined_progress = mode == "combined"
-        self.full_stats = stats == "full"
 
         self._progress = self.create_progress_bar(
             progress_columns,