ERR: Improve error message in validate_percentile

pandas/tests/util/test_validator.py

@@ -0,0 +1,12 @@
+import numpy as np
+import pytest
+
+import pandas as pd
+
+
+def test_series_quantile_invalid_percentile():
+    s = pd.Series(np.random.randn(100))
+    percentile_array = [-0.5, 0.25, 1.5]
+    msg = "percentiles should all be in the interval \\[0, 1\\]"
+    with pytest.raises(ValueError, match=msg):
+        s.quantile(percentile_array)

pandas/util/_validators.py

@@ -326,12 +326,13 @@ def validate_percentile(q: float | Iterable[float]) -> np.ndarray:
     q_arr = np.asarray(q)
     # 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."
+    msg = "percentiles should all be in the interval [0, 1]"
     if q_arr.ndim == 0:
         if not 0 <= q_arr <= 1:
-            raise ValueError(msg.format(q_arr / 100.0))
-    elif not all(0 <= qs <= 1 for qs in q_arr):
-        raise ValueError(msg.format(q_arr / 100.0))
+            raise ValueError(msg)
+    else:
+        if not all(0 <= qs <= 1 for qs in q_arr):
+            raise ValueError(msg)
     return q_arr