使用itertools.groupby()按特定键（如第一个字母）对输入进行分组：

from itertools import groupby
from operator import itemgetter

for letter, words in groupby(sorted(somelist), key=itemgetter(0)):
    print letter
    for word in words:
        print word
    print

如果列表已经排序，可以省略sorted()调用。itemgetter(0)可调用函数将返回每个单词的首字母（索引0处的字符），并且groupby()然后将产生该键加上仅由键保持相同的那些项组成的可迭代项。在本例中，这意味着在words上循环会得到以相同字符开头的所有项。
演示：

>>> somelist = ['About', 'Absolutely', 'After', 'Aint', 'Alabama', 'AlabamaBill', 'All', 'Also', 'Amos', 'And', 'Anyhow', 'Are', 'As', 'At', 'Aunt', 'Aw', 'Bedlam', 'Behind', 'Besides', 'Biblical', 'Bill', 'Billgone']
>>> from itertools import groupby
>>> from operator import itemgetter
>>> 
>>> for letter, words in groupby(sorted(somelist), key=itemgetter(0)):
...     print letter
...     for word in words:
...         print word
...     print
... 
A
About
Absolutely
After
Aint
Alabama
AlabamaBill
All
Also
Amos
And
Anyhow
Are
As
At
Aunt
Aw

B
Bedlam
Behind
Besides
Biblical
Bill
Billgone

而不是使用任何库导入，或者任何花哨的东西。逻辑如下：

def splitLst(x):
    dictionary = dict()
    for word in x:
       f = word[0]
       if f in dictionary.keys():
            dictionary[f].append(word)
       else:
            dictionary[f] = [word]
     return dictionary

splitLst(['About', 'Absolutely', 'After', 'Aint', 'Alabama', 'AlabamaBill', 'All', 'Also', 'Amos', 'And', 'Anyhow', 'Are', 'As', 'At', 'Aunt', 'Aw', 'Bedlam', 'Behind', 'Besides', 'Biblical', 'Bill', 'Billgone'])

定义拆分（n）：对于n中的i，n2 = []：如果i[0]不在n2中：n2.附加（i[0]）n2.排序（）用于n中的j：z = j[0] z1 = n2.索引（z）n2.插入（z1+1，j）返回n2
word_list =[“是”、“有”、“做”、“说”、"得到“、”制造“、”去“、”知道“、”拿“、”看到“、”来“、”想“、”看“、”想要“、”给予“、”使用“、”查找“、”告诉“、”询问“、”工作“、”似乎“、”感觉“、”离开“、”呼叫“] print（split（word_list））