Python元组列表

Question

你能帮我转换一下Python列表:

[(1, 'a'), (2, 'b'), (2, 'c'), (3, 'd'), (3, 'e')]

所以: (1, 'a')是索引0

(2, 'b'), (2, 'c') 都是索引1

(3, 'd'), (3, 'e') 都是索引2

简单地说,元素[0]相等的所有元组都具有相同的索引.

谢谢,

Answer 1

itertools.groupby 救援!:

lst = [(1, 'a'), (2, 'b'), (2, 'c'), (3, 'd'), (3, 'e')]
lst.sort(key=lambda x: x[0])  #Only necessary if your list isn't sorted already.
new_lst = [list(v) for k,v in itertools.groupby(lst,key=lambda x:x[0])]

你可以用operator.itemgetter(0)而不是lambda你想要的......

演示:

>>> import itertools
>>> lst = [(1, 'a'), (2, 'b'), (2, 'c'), (3, 'd'), (3, 'e')]
>>> lst.sort(key=lambda x: x[0])
>>> new_lst = [list(v) for k,v in itertools.groupby(lst,key=lambda x:x[0])]
>>> new_lst
[[(1, 'a')], [(2, 'b'), (2, 'c')], [(3, 'd'), (3, 'e')]]