Apply new string format syntax to exception string

Joschua-Conrad · QuLogic · web-flow · commit 5319e8935b05 · 2021-04-27T08:23:39.000+02:00
Co-authored-by: Elliott Sales de Andrade &lt;quantum.analyst@gmail.com&gt;
diff --git a/examples/widgets/annotated_cursor.py b/examples/widgets/annotated_cursor.py
@@ -237,9 +237,8 @@ def setpos(self, xpos, ypos):
             data = ydata
             lim = self.ax.get_ylim()
         else:
-            raise ValueError(
-                "The data axis specifier {} should be 'x' or 'y'"
-                .format(self.dataaxis))
+            raise ValueError(f"The data axis specifier {self.dataaxis} should "
+                             f"be 'x' or 'y'")
 
         # If position is valid
         if pos is not None:
