code: def test_eng_float_formatter(self):
      df = DataFrame({"A": [1.41, 141.0, 14100, 1410000.0]})
  
      set_eng_float_format()
      result = df.to_string()
      expected = (
          "             A\n"
          "0    1.410E+00\n"
          "1  141.000E+00\n"
          "2   14.100E+03\n"
          "3    1.410E+06"
      )
      assert result == expected
  
      set_eng_float_format(use_eng_prefix=True)
      result = df.to_string()
      expected = (
          "         A\n0    1.410\n1  141.000\n2  14.100k\n3   1.410M"
      )
      assert result == expected
  
      set_eng_float_format(accuracy=0)
      result = df.to_string()
      expected = (
          "         A\n0    1E+00\n1  141E+00\n2   14E+03\n3    1E+06"
      )
      assert result == expected
  
file_path: pandas/pandas/tests/io/formats/test_eng_formatting.py
imports: import numpy
  import pytest
  from pandas import DataFrame, reset_option, set_eng_float_format
  from pandas.io.formats.format import EngFormatter
label_desc: Use image node_id 2 for calling the TestEngFormatter obj's underlying member method code with example usage: obj.test_eng_float_formatter() without return types