Data = [
'<td>1</td>', '<td>2</td>', '<td>3</td>', '<td>4</td>',
'<td>A</td>', '<td>B</td>', '<td>C</td>', '<td>D</td>',
'<td>I</td>', '<td>II</td>', '<td>III</td>', '<td>IV</td>',
]
lists, result = [], []
for i in range(0, len(Data), 4):
lists.append(Data[i:i+4])
for currentList in zip(*lists):
result += list(currentList)
print result
Output
['<td>1</td>', '<td>A</td>', '<td>I</td>',
'<td>2</td>', '<td>B</td>', '<td>II</td>',
'<td>3</td>', '<td>C</td>', '<td>III</td>',
'<td>4</td>', '<td>D</td>', '<td>IV</td>']
solved Python sort list by algorithm [closed]