Python:对文本文件进行两次排序并拆分为不同的文件？

Question

如何首先按行长度排序，然后按字母顺序排序，然后按行长度拆分为单独的文件？ 我有一个单词列表文件，如下所示:

a

actors

an

b

batter

but

我需要每个行长度一个文件(1.txt、2.txt)，每个文件按字母顺序排序。这可以如何完成？

生成的文件应如下所示:

1.txt

a
b
...

2.txt

an
by
...

等等

Answer 1

from collections import defaultdict

OUTF = "{0}.txt".format

def sortWords(wordList):
    d = defaultdict(list)
    for word in wordList:
        d[len(word)].append(word)
    return d

def readWords(fname):
    with open(fname) as inf:
        return [word for word in (line.strip() for line in inf.readlines()) if word]

def writeWords(fname, wordList):
    wordList.sort()
    with open(fname, 'w') as outf:
        outf.write('\n'.join(wordList))

def main():
    for wordLen,wordList in sortWords(readWords('words.txt')).iteritems():
        writeWords(OUTF(wordLen), wordList)

if __name__=="__main__":
    main()