如何从以下列表中创建 pandas DataFrame:
ls= \
[['41457', 'PRE', '533', '887', '1/3/1978', '2/1/2008', '[REL]', '217', '197800000003'],\
['41458', 'PRE', '533', '887', '1/3/1978', '2/1/2008', '[REL]', '217', '197800000004'],\
['41460', 'PRE', '780', '887', '1/3/1978', '2/1/2008', '[D/T]', '217', '197800000006'],\
['41461', 'PRE', '780', '887', '1/3/1978', '2/1/2008', '[D/T]', '217', '197800000007'],\
['41462', 'PRE', '645', '887', '1/3/1978', '2/1/2008', '[AGREE]', '217', '197800000008'],\
['41463', 'PRE', '645', '887', '1/3/1978', '2/1/2008', '[AGREE]', '217', '197800000009'],\
['41464', 'PRE', '645', '887', '1/3/1978', '2/1/2008', '[AGREE]', '217', '197800000010'],\
['41465', 'PRE', '645', '887', '1/3/1978', '2/1/2008', '[AGREE]', '217', '197800000011'],\
['41489', 'PRE', '533', '887', '1/3/1978', '2/1/2008', '[REL]', '492', '197800000035']]
并将第一个元素 '41457', '41458' ... '41489' 作为索引。