Python 3.8 字典值按字母顺序排序

Question

此代码用于读取文本文件并将每个单词添加到字典中，其中键是第一个字母，值是文件中以该字母开头的所有单词。它有点工作，但对于 我遇到了两个问题：

1. 字典键包含撇号和句号（如何排除？）
2. 这些值不是按字母顺序排列的，而且都是乱七八糟的。代码最终输出如下内容：

' - {"don't", "i'm", "let's"}
. - {'below.', 'farm.', 'them.'}
a - {'take', 'masters', 'can', 'fallow'}
b - {'barnacle', 'labyrinth', 'pebble'}
...
...
y - {'they', 'very', 'yellow', 'pastry'}

什么时候应该更像：

a - {'ape', 'army','arrow', 'arson',}
b - {'bank', 'blast', 'blaze', 'breathe'}
etc

# make empty dictionary
dic = {}

# read file
infile = open('file.txt', "r")

# read first line
lines = infile.readline()
while lines != "":
    # split the words up and remove "\n" from the end of the line
    lines = lines.rstrip()
    lines = lines.split()

    for word in lines:
        for char in word: 
            # add if not in dictionary
             if char not in dic: 
                dic[char.lower()] = set([word.lower()])
            # Else, add word to set
             else:
                dic[char.lower()].add(word.lower())
    # Continue reading
    lines = infile.readline()

# Close file
infile.close()

# Print
for letter in sorted(dic): 
    print(letter + " - " + str(dic[letter]))

我猜我在第一次遍历文件时需要从整个文件中删除标点符号和撇号，但在向字典中添加任何内容之前？但是，在以正确的顺序获取值时完全迷失了。

Answer 1

在删除任何起始标点符号后使用defaultdict(set) 和dic[word[0]].add(word)。不需要内循环。

Answer 2

from collections import defaultdict


def process_file(fn):
    my_dict = defaultdict(set)
    for word in open(fn, 'r').read().split():
        if word[0].isalpha():
            my_dict[word[0].lower()].add(word)
    return(my_dict)


word_dict = process_file('file.txt') 
for letter in sorted(word_dict): 
    print(letter + " - " + ', '.join(sorted(word_dict[letter])))

Answer 3

你有很多问题

1. 在空格和标点符号上分割单词
2. 将单词添加到第一次添加时不存在的集合中
3. 对输出进行排序

这是一个尝试解决上述问题的小程序

import re, string

# instead of using "text = open(filename).read()" we exploit a piece
# of text contained in one of the imported modules
text = re.__doc__

# 1. how to split at once the text contained in the file
#
# credit to https://stackoverflow.com/a/13184791/2749397
p_ws = string.punctuation + string.whitespace
words = re.split('|'.join(re.escape(c) for c in p_ws), text)

# 2. how to instantiate a set when we do the first addition to a key,
#    that is, using the .setdefault method of every dictionary
d = {}
# Note: words regularized by lowercasing, we skip the empty tokens    
for word in (w.lower() for w in words if w):
    d.setdefault(word[0], set()).add(word)

# 3. how to print the sorted entries corresponding to each letter
for letter in sorted(d.keys()):
    print(letter, *sorted(d[letter]))

我的text 包含数字，因此可以在上述程序的输出（见下文）中找到数字；如果你不想用数字过滤它们，if letter not in '0123456789': print(...)。

这是输出...

0 0
1 1
8 8
9 9
a a above accessible after ailmsux all alphanumeric alphanumerics also an and any are as ascii at available
b b backslash be before beginning behaviour being below bit both but by bytes
c cache can case categories character characters clear comment comments compatibility compile complement complementing concatenate consist consume contain contents corresponding creates current
d d decimal default defined defines dependent digit digits doesn dotall
e each earlier either empty end equivalent error escape escapes except exception exports expression expressions
f f find findall finditer first fixed flag flags following for forbidden found from fullmatch functions
g greedy group grouping
i i id if ignore ignorecase ignored in including indicates insensitive inside into is it iterator
j just
l l last later length letters like lines list literal locale looking
m m made make many match matched matches matching means module more most multiline must
n n name named needn newline next nicer no non not null number
o object occurrences of on only operations optional or ordinary otherwise outside
p p parameters parentheses pattern patterns perform perl plus possible preceded preceding presence previous processed provides purge
r r range rather re regular repetitions resulting retrieved return
s s same search second see sequence sequences set signals similar simplest simply so some special specified split start string strings sub subn substitute substitutions substring support supports
t t takes text than that the themselves then they this those three to
u u underscore unicode us
v v verbose version versions
w w well which whitespace whole will with without word
x x
y yes yielding you
z z z0 za

---

没有 cmets 和一点混淆，它只是 3 行代码......

import re, string
text = re.__doc__
p_ws = string.punctuation + string.whitespace
words = re.split('|'.join(re.escape(c) for c in p_ws), text)

d, add2d = {}, lambda w: d.setdefault(w[0],set()).add(w) #1
for word in (w.lower() for w in words if w): add2d(word) #2
for abc in sorted(d.keys()): print(abc, *sorted(d[abc])) #3