如何将元组列表转换为元组？

Question

我如何变换

[(212, u'comment', 0L), (205, u'main', 0L)] 

变成这样？

(0L, 0L) 

Answer 1

>>> data = [(212, u'comment', 0L), (205, u'main', 0L)] 
>>> tuple(x[2] for x in data) 
(0L, 0L) 

或其它方法......

>>> zip(*data) # just showing what zip(*data) does 
[(212, 205), (u'comment', u'main'), (0L, 0L)] 
>>> zip(*data)[2] 
(0L, 0L) 

使用itertools.imap()和operator.itemgetter() ...

>>> from itertools import imap 
>>> from operator import itemgetter 
>>> tuple(imap(itemgetter(2), data)) 
(0L, 0L)