def test_fill_back1():
	testing_df =df.copy()
	clean.fillDown(testing_df, 0, 1, 'bfill')
	res = {'col1' : pd.Series([1., 2., 3., 3., 4.], index=[0, 1, 2, 3, 4]),
	'col2' : pd.Series([1., 2., 2., 4., 4.], index=[0, 1, 2, 3, 4]),
	'col3' : pd.Series([1., 2., 3., 4., 5.,])}
	df_res = pd.DataFrame(res)
	assert (((testing_df.fillna(0) == df_res.fillna(0)).all()).all()) == True
def test_fill_back2():
	testing_df = df.copy()
	clean.fillDown(testing_df, 2, 2, 'bfill')
	assert (((testing_df.fillna(0) == df.fillna(0)).all()).all()) == True
def test_fill_pad4():
	testing_df = df.copy() 
	clean.fillDown(testing_df, 1, 0,'pad')
	with pytest.raises(Exception):
		clean.fillDown(testing_df, 3, 3, 'pad')
def test_fill_pad3():
	testing_df = df.copy
	with pytest.raises(Exception):
		clean.fillDown(testing_df, 4, 4, 'pad')