diff --git a/pandas/io/tests/parser/comment.py b/pandas/io/tests/parser/comment.py index f7cd1e190ec16..9987a017cf985 100644 --- a/pandas/io/tests/parser/comment.py +++ b/pandas/io/tests/parser/comment.py @@ -104,3 +104,15 @@ def test_custom_comment_char(self): result = self.read_csv(StringIO(data), comment='#') expected = DataFrame({'a': [1, 4], 'b': [2, 5], 'c': [3, 6]}) tm.assert_frame_equal(result, expected) + + def test_commment_first_line(self): + # see gh-4623 + data = '# notes\na,b,c\n# more notes\n1,2,3' + + expected = DataFrame([[1, 2, 3]], columns=['a', 'b', 'c']) + result = self.read_csv(StringIO(data), comment='#') + tm.assert_frame_equal(result, expected) + + expected = DataFrame({0: ['a', '1'], 1: ['b', '2'], 2: ['c', '3']}) + result = self.read_csv(StringIO(data), comment='#', header=None) + tm.assert_frame_equal(result, expected)