CLN avoid more test warnings (#50621)

Author: MarcoGorelli

pandas/tests/frame/methods/test_describe.py

@@ -388,7 +388,9 @@ def test_ea_with_na(self, any_numeric_ea_dtype):
  # GH#48778
 
  df = DataFrame({"a": [1, pd.NA, pd.NA], "b": pd.NA}, dtype=any_numeric_ea_dtype)
- result = df.describe()
+ # Warning from numpy for taking std of single element
+ with tm.assert_produces_warning(RuntimeWarning, check_stacklevel=False):
+ result = df.describe()
  expected = DataFrame(
  {"a": [1.0, 1.0, pd.NA] + [1.0] * 5, "b": [0.0] + [pd.NA] * 7},
  index=["count", "mean", "std", "min", "25%", "50%", "75%", "max"],

pandas/tests/frame/methods/test_shift.py

@@ -397,6 +397,13 @@ def test_shift_axis1_multiple_blocks(self, using_array_manager):
  result = df3.shift(2, axis=1)
 
  expected = df3.take([-1, -1, 0, 1, 2], axis=1)
+ # Explicit cast to float to avoid implicit cast when setting nan.
+ # Column names aren't unique, so directly calling `expected.astype` won't work.
+ expected = expected.pipe(
+ lambda df: df.set_axis(range(df.shape[1]), axis=1)
+ .astype({0: "float", 1: "float"})
+ .set_axis(df.columns, axis=1)
+ )
  expected.iloc[:, :2] = np.nan
  expected.columns = df3.columns
 
@@ -410,6 +417,13 @@ def test_shift_axis1_multiple_blocks(self, using_array_manager):
  result = df3.shift(-2, axis=1)
 
  expected = df3.take([2, 3, 4, -1, -1], axis=1)
+ # Explicit cast to float to avoid implicit cast when setting nan.
+ # Column names aren't unique, so directly calling `expected.astype` won't work.
+ expected = expected.pipe(
+ lambda df: df.set_axis(range(df.shape[1]), axis=1)
+ .astype({3: "float", 4: "float"})
+ .set_axis(df.columns, axis=1)
+ )
  expected.iloc[:, -2:] = np.nan
  expected.columns = df3.columns