我有一组标记为item_labels = [(‘a’,3),(‘b’,2),(‘c’,1),(‘d’,3),(‘e’, 2),(‘f’,3)]
我想按组的大小对它们进行排序.例如,在上面的例子中,标签3的尺寸为3,标签2的尺寸为2.
我尝试使用groupby和sorted的组合,但没有工作.
In [162]: sil = sorted(item_labels, key=op.itemgetter(1))
In [163]: sil
Out[163]: [('c', 1), ('b', 2), ('e', 2), ('a', 3), ('d', 3), ('f', 3)]
In [164]: g = itt.groupby(sil,)
Display all 465 possibilities? (y or n)
In [164]: g = itt.groupby(sil, key=op.itemgetter(1))
In [165]: for k, v in g:
.....: print k, list(v)
.....:
.....:
1 [('c', 1)]
2 [('b', 2), ('e', 2)]
3 [('a', 3), ('d', 3), ('f', 3)]
In [166]: sg = sorted(g, key=lambda x: len(list(x[1])))
In [167]: sg
Out[167]: [] # not exactly know why I got an empty list here
我总是可以写一些乏味的for循环来做这件事,但我宁愿找到更优雅的东西.有什么建议吗？如果有有用的库我很乐意使用它.例如,熊猫,scipy
