Stop calling float() on single element Series (facebook#2691)

Summary:
Pull Request resolved: facebook#2691

This practice was causing a deprecation warning: `Calling float on a single element Series is deprecated and will raise a TypeError in the future.`

Reviewed By: bernardbeckerman

Differential Revision: D61612829

fbshipit-source-id: 955b41b8e6b4f59be14db0363c575995e4b0b481

ax/core/tests/test_data.py

@@ -90,10 +90,12 @@ def test_Data(self) -> None:
 
  df = data.df
  self.assertEqual(
- float(df[df["arm_name"] == "0_0"][df["metric_name"] == "a"]["mean"]), 2.0
+ float(df[df["arm_name"] == "0_0"][df["metric_name"] == "a"]["mean"].item()),
+ 2.0,
  )
  self.assertEqual(
- float(df[df["arm_name"] == "0_1"][df["metric_name"] == "b"]["sem"]), 0.5
+ float(df[df["arm_name"] == "0_1"][df["metric_name"] == "b"]["sem"].item()),
+ 0.5,
  )
 
  def test_BadData(self) -> None:

ax/core/tests/test_multi_type_experiment.py

@@ -48,8 +48,8 @@ def test_MTExperimentFlow(self) -> None:
 
  arm_0_slice = df.loc[df["arm_name"] == "0_0"]
  self.assertNotEqual(
- float(arm_0_slice[df["trial_index"] == 0]["mean"]),
- float(arm_0_slice[df["trial_index"] == 1]["mean"]),
+ float(arm_0_slice[df["trial_index"] == 0]["mean"].item()),
+ float(arm_0_slice[df["trial_index"] == 1]["mean"].item()),
  )
  self.assertEqual(len(df), 2 * n)
  self.assertEqual(self.experiment.default_trials, {0})
@@ -60,8 +60,8 @@ def test_MTExperimentFlow(self) -> None:
  df = self.experiment.fetch_data().df
  arm_0_slice = df.loc[df["arm_name"] == "0_0"]
  self.assertAlmostEqual(
- float(arm_0_slice[df["trial_index"] == 0]["mean"]),
- float(arm_0_slice[df["trial_index"] == 1]["mean"]),
+ float(arm_0_slice[df["trial_index"] == 0]["mean"].item()),
+ float(arm_0_slice[df["trial_index"] == 1]["mean"].item()),
  places=10,
  )