code: def test_interp_various(self):
      pytest.importorskip("scipy")
      df = DataFrame(
          {
              "A": [1, 2, np.nan, 4, 5, np.nan, 7],
              "C": [1, 2, 3, 5, 8, 13, 21],
          }
      )
      df = df.set_index("C")
      expected = df.copy()
      result = df.interpolate(method="polynomial", order=1)
  
      expected.loc[3, "A"] = 2.66666667
      expected.loc[13, "A"] = 5.76923076
      tm.assert_frame_equal(result, expected)
  
      result = df.interpolate(method="cubic")
      # GH #15662.
      expected.loc[3, "A"] = 2.81547781
      expected.loc[13, "A"] = 5.52964175
      tm.assert_frame_equal(result, expected)
  
      result = df.interpolate(method="nearest")
      expected.loc[3, "A"] = 2
      expected.loc[13, "A"] = 5
      tm.assert_frame_equal(result, expected, check_dtype=False)
  
      result = df.interpolate(method="quadratic")
      expected.loc[3, "A"] = 2.82150771
      expected.loc[13, "A"] = 6.12648668
      tm.assert_frame_equal(result, expected)
  
      result = df.interpolate(method="slinear")
      expected.loc[3, "A"] = 2.66666667
      expected.loc[13, "A"] = 5.76923077
      tm.assert_frame_equal(result, expected)
  
      result = df.interpolate(method="zero")
      expected.loc[3, "A"] = 2.0
      expected.loc[13, "A"] = 5
      tm.assert_frame_equal(result, expected, check_dtype=False)
  
imports: import numpy
  import pytest
  from pandas._config import using_pyarrow_string_dtype
  from pandas.errors import ChainedAssignmentError
  import pandas.util._test_decorators
  from pandas import DataFrame, NaT, Series, date_range
  import pandas._testing
label_desc: Use image node_id 11 for calling the TestDataFrameInterpolate obj's underlying member method code with example usage: obj.test_interp_various() without return types