python2.7中列表和元组间的转化，如何将一个包含元组的列表变成一个列表，具体如下所示。

Question

如何将aaa=[[('s1',)], [('s1',)], [('s1',)], [('s1', 's2')], [('s1', 's2')], [('s1', 's2')], [('s1', 's2')]] 变成bbb= [['s1'], ['s1'], [s1'], ['s1','s2'], ['s1', 's2'], ['s1', 's2'], ['s1', 's2']]，请大牛用python代码实现

Answer 1

aaa=[[('s1',)], [('s1',)], [('s1',)], [('s1', 's2')], [('s1', 's2')], [('s1', 's2')], [('s1', 's2')]]

bbb=[]

for each in aaa:
    for ec in each:
        bbb.append(list(ec))

Answer 2

[list(i[0]) for i in aaa]