拆分根據字符內長度在子列表的列表

Question

我有字符串的列表，我喜歡根據在第列表例如單詞的字符長度來分割該列表在不同的「子列表」：

List = [a, bb, aa, ccc, dddd] 

Sublist1 = [a] 
Sublist2= [bb, aa] 
Sublist3= [ccc] 
Sublist2= [dddd] 

我如何在Python中實現這一點？

謝謝

Answer 1

我認爲你應該使用字典

>>> dict_sublist = {} 
>>> for el in List: 
...  dict_sublist.setdefault(len(el), []).append(el) 
... 
>>> dict_sublist 
{1: ['a'], 2: ['bb', 'aa'], 3: ['ccc'], 4: ['dddd']} 

Answer 2

假設你滿意的清單列表，按長度索引，如何像

by_length = [] 
for word in List: 
    wl = len(word) 
    while len(by_length) < wl: 
     by_length.append([]) 
    by_length[wl].append(word) 

print "The words of length 3 are %s" % by_length[3]  

Answer 3

通過使用itertools.groupby：

values = ['a', 'bb', 'aa', 'ccc', 'dddd', 'eee'] 
from itertools import groupby 
output = [list(group) for key,group in groupby(sorted(values, key=len), key=len)] 

結果是：

[['a'], ['bb', 'aa'], ['ccc', 'eee'], ['dddd']] 

如果列表已經按字符串長度排序，你只需要做分組，那麼你就可以簡化代碼：

output = [list(group) for key,group in groupby(values, key=len)] 

Answer 4

>>> from collections import defaultdict 
>>> l = ["a", "bb", "aa", "ccc", "dddd"] 
>>> d = defaultdict(list) 
>>> for elem in l: 
...  d[len(elem)].append(elem) 
... 
>>> sublists = list(d.values()) 
>>> print(sublists) 
[['a'], ['bb', 'aa'], ['ccc'], ['dddd']]