def test_auto_column_header(self):
column = TableColumn()
column.column_index = 1
self.assertFalse(column._header)
header = column.header
self.assertIsInstance(header, str)
self.assertTrue(header)
def test_column_letter(self):
column = TableColumn()
for i in range(1, 20):
column.column_index = i
self.assertEqual(column.column_letter, chr(ord('A') + i - 1))