code: def test_quantile_nan(self, interp_method):
      interpolation, method = interp_method
      # GH 14357 - float block where some cols have missing values
      df = DataFrame({"a": np.arange(1, 6.0), "b": np.arange(1, 6.0)})
      df.iloc[-1, 1] = np.nan
  
      res = df.quantile(0.5, interpolation=interpolation, method=method)
      exp = Series(
          [3.0, 2.5 if interpolation == "linear" else 3.0],
          index=["a", "b"],
          name=0.5,
      )
      tm.assert_series_equal(res, exp)
  
      res = df.quantile(
          [0.5, 0.75], interpolation=interpolation, method=method
      )
      exp = DataFrame(
          {
              "a": [3.0, 4.0],
              "b": [2.5, 3.25]
              if interpolation == "linear"
              else [3.0, 4.0],
          },
          index=[0.5, 0.75],
      )
      tm.assert_frame_equal(res, exp)
  
      res = df.quantile(
          0.5, axis=1, interpolation=interpolation, method=method
      )
      exp = Series(np.arange(1.0, 6.0), name=0.5)
      tm.assert_series_equal(res, exp)
  
      res = df.quantile(
          [0.5, 0.75],
          axis=1,
          interpolation=interpolation,
          method=method,
      )
      exp = DataFrame([np.arange(1.0, 6.0)] * 2, index=[0.5, 0.75])
      if interpolation == "nearest":
          exp.iloc[1, -1] = np.nan
      tm.assert_frame_equal(res, exp)
  
      # full-nan column
      df["b"] = np.nan
  
      res = df.quantile(0.5, interpolation=interpolation, method=method)
      exp = Series([3.0, np.nan], index=["a", "b"], name=0.5)
      tm.assert_series_equal(res, exp)
  
      res = df.quantile(
          [0.5, 0.75], interpolation=interpolation, method=method
      )
      exp = DataFrame(
          {"a": [3.0, 4.0], "b": [np.nan, np.nan]}, index=[0.5, 0.75]
      )
      tm.assert_frame_equal(res, exp)
  
imports: import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Index, Series, Timestamp
  import pandas._testing
label_desc: Use image node_id 21 for calling the TestDataFrameQuantile obj's underlying member method code with example usage: obj.test_quantile_nan(interp_method) without return types