Update backtesting/_plotting.py

Co-authored-by: kernc <[email protected]>

Author: ivaigult

backtesting/_plotting.py

@@ -538,15 +538,18 @@ def __eq__(self, other):
             colors = colors and cycle(_as_list(colors)) or (
                 cycle([next(ohlc_colors)]) if is_overlay else colorgen())
 
-            tooltip_label = value.name if isinstance(value.name, str) else ", ".join(value.name)
-
-            if isinstance(value.name, str) and len(value) > 1:
-                legend_labels = [
-                    LegendStr(f"{name}[{index}]")
-                    for index, name in enumerate(repeat(value.name, len(value)))
-                ]
+            if isinstance(value.name, str):
+                tooltip_label = value.name
+                if len(value) == 1:
+                    legend_labels = [LegendStr(value.name)]
+                else:
+                    legend_labels = [
+                        LegendStr(f"{value.name}[{i}]")
+                        for i in enumerate(len(value))
+                    ]
             else:
-                legend_labels = [LegendStr(item) for item in _as_list(value.name)]
+                tooltip_label = ", ".join(value.name)
+                legend_labels = [LegendStr(item) for item in value.name]
 
             for j, arr in enumerate(value):
                 color = next(colors)