PERF: Fix quantile perf regression (#35101)

pandas/util/_validators.py

@@ -371,14 +371,13 @@ def validate_percentile(q: Union[float, Iterable[float]]) -> np.ndarray:
     ValueError if percentiles are not in given interval([0, 1]).
     """
     q_arr = np.asarray(q)
-    msg = (
-        "percentiles should all be in the interval [0, 1]."
-        f"Try {q_arr / 100.0} instead."
-    )
+    # Don't change this to an f-string. The string formatting
+    # is too expensive for cases where we don't need it.
+    msg = "percentiles should all be in the interval [0, 1]. Try {} instead."
     if q_arr.ndim == 0:
         if not 0 <= q_arr <= 1:
-            raise ValueError(msg)
+            raise ValueError(msg.format(q_arr / 100.0))
     else:
         if not all(0 <= qs <= 1 for qs in q_arr):
-            raise ValueError(msg)
+            raise ValueError(msg.format(q_arr / 100.0))
     return q_arr