test_format.py 文件源码

def test_to_csv_na_rep(self):
        # testing if NaN values are correctly represented in the index
        # GH 11553
        df = DataFrame({'a': [0, np.NaN], 'b': [0, 1], 'c': [2, 3]})
        expected = "a,b,c\n0.0,0,2\n_,1,3\n"
        self.assertEqual(df.set_index('a').to_csv(na_rep='_'), expected)
        self.assertEqual(df.set_index(['a', 'b']).to_csv(na_rep='_'), expected)

        # now with an index containing only NaNs
        df = DataFrame({'a': np.NaN, 'b': [0, 1], 'c': [2, 3]})
        expected = "a,b,c\n_,0,2\n_,1,3\n"
        self.assertEqual(df.set_index('a').to_csv(na_rep='_'), expected)
        self.assertEqual(df.set_index(['a', 'b']).to_csv(na_rep='_'), expected)

        # check if na_rep parameter does not break anything when no NaN
        df = DataFrame({'a': 0, 'b': [0, 1], 'c': [2, 3]})
        expected = "a,b,c\n0,0,2\n0,1,3\n"
        self.assertEqual(df.set_index('a').to_csv(na_rep='_'), expected)
        self.assertEqual(df.set_index(['a', 'b']).to_csv(na_rep='_'), expected)