Python重复字

我有一个问题，我必须计算Python（v3.4.1）中的重复单词，并将它们放在一个句子中。我使用了计数器，但我不知道如何按以下顺序获得输出。输入为：

mysentence = As far as the laws of mathematics refer to reality they are not certain as far as they are certain they do not refer to reality

我把它列成了一个列表，并对它进行了排序

假设输出是这样的

"As" is repeated 1 time.
"are" is repeated 2 times.
"as" is repeated 3 times.
"certain" is repeated 2 times.
"do" is repeated 1 time.
"far" is repeated 2 times.
"laws" is repeated 1 time.
"mathematics" is repeated 1 time.
"not" is repeated 2 times.
"of" is repeated 1 time.
"reality" is repeated 2 times.
"refer" is repeated 2 times.
"the" is repeated 1 time.
"they" is repeated 3 times.
"to" is repeated 2 times.

到目前为止，我已经谈到这一点

x=input ('Enter your sentence :')
y=x.split()
y.sort()
for y in sorted(y):
    print (y)

---

我可以看到排序的方向，因为您可以可靠地知道何时找到一个新词，并跟踪每个唯一单词的计数。然而，您真正想要做的是使用哈希（字典）来跟踪计数，因为字典键是唯一的。例如：

words = sentence.split()
counts = {}
for word in words:
    if word not in counts:
        counts[word] = 0
    counts[word] += 1

现在，这将为您提供一个字典，其中关键字是单词，值是它出现的次数。您可以使用

collections.defaultdict（int）

等方法来添加值：

counts = collections.defaultdict(int)
for word in words:
    counts[word] += 1

但还有比这更好的东西

collections.计数器

，它会将您的单词列表转换为包含计数的词典（实际上是词典的扩展）

counts = collections.Counter(words)

从那里，您需要按排序的单词列表及其计数，以便您可以打印它们

items（）

将为您提供一个元组列表，

sorted

将按每个元组的第一项（本例中的单词）进行排序（默认情况下）。。。这正是你想要的

import collections
sentence = """As far as the laws of mathematics refer to reality they are not certain as far as they are certain they do not refer to reality"""
words = sentence.split()
word_counts = collections.Counter(words)
for word, count in sorted(word_counts.items()):
    print('"%s" is repeated %d time%s.' % (word, count, "s" if count > 1 else ""))

输出

"As" is repeated 1 time.
"are" is repeated 2 times.
"as" is repeated 3 times.
"certain" is repeated 2 times.
"do" is repeated 1 time.
"far" is repeated 2 times.
"laws" is repeated 1 time.
"mathematics" is repeated 1 time.
"not" is repeated 2 times.
"of" is repeated 1 time.
"reality" is repeated 2 times.
"refer" is repeated 2 times.
"the" is repeated 1 time.
"they" is repeated 3 times.
"to" is repeated 2 times.

---

下面是一个非常糟糕的示例，说明在不使用列表以外的任何内容的情况下执行此操作：

x = "As far as the laws of mathematics refer to reality they are not certain as far as they are certain they do not refer to reality"
words = x.split(" ")
words.sort()

words_copied = x.split(" ")
words_copied.sort()

for word in words:
    count = 0
    while(True):
        try:
            index = words_copied.index(word)
            count += 1
            del words_copied[index]
        except ValueError:
            if count is not 0:
                print(word + " is repeated " + str(count) + " times.")
            break

编辑：这里有一个更好的方法：

x = "As far as the laws of mathematics refer to reality they are not certain as far as they are certain they do not refer to reality"
words = x.split(" ")
words.sort()

last_word = ""
for word in words:
    if word != last_word:
        count = [i for i, w in enumerate(words) if w == word]
        print(word + " is repeated " + str(len(count)) + " times.")
    last_word = word

---

要按排序顺序打印字符串中的单词副本，请执行以下操作：

from itertools import groupby 

mysentence = ("As far as the laws of mathematics refer to reality "
              "they are not certain as far as they are certain "
              "they do not refer to reality")
words = mysentence.split() # get a list of whitespace-separated words
for word, duplicates in groupby(sorted(words)): # sort and group duplicates
    count = len(list(duplicates)) # count how many times the word occurs
    print('"{word}" is repeated {count} time{s}'.format(
            word=word, count=count,  s='s'*(count > 1)))

“As”重复1次 “are”重复2次 “as”重复3次 “确定”重复2次 “do”重复1次 “远”重复2次 “定律”重复一次 “数学”重复一次 “不”重复2次 “of”重复1次 “现实”重复2次 “参考”重复2次 “the”重复一次 “他们”重复3次 “to”重复2次

---

嘿，我已经在Python2.7（mac）上试过了，因为我有那个版本，所以试着掌握逻辑

from collections import Counter

mysentence = """As far as the laws of mathematics refer to reality they are not certain as far as they are certain they do not refer to reality"""

mysentence = dict(Counter(mysentence.split()))
for i in sorted(mysentence.keys()):
    print ('"'+i+'" is repeated '+str(mysentence[i])+' time.')

我希望这是你正在寻找的，如果不是的话，那么请让我高兴地学习新的东西

"As" is repeated 1 time.
"are" is repeated 2 time.
"as" is repeated 3 time.
"certain" is repeated 2 time.
"do" is repeated 1 time.
"far" is repeated 2 time.
"laws" is repeated 1 time.
"mathematics" is repeated 1 time.
"not" is repeated 2 time.
"of" is repeated 1 time.
"reality" is repeated 2 time.
"refer" is repeated 2 time.
"the" is repeated 1 time.
"they" is repeated 3 time.
"to" is repeated 2 time.

---

你应该看看collections.Counter类。这与您的用例非常相关。@ChrisArena：他在第一句话“我使用了计数器”…为什么所有变量都被称为

y

？你是想让你的代码变得混乱，还是你的其他大部分钥匙都坏了？@abarnert我不确定他是不是想说，在官方的“计数器”意义上，他是想数一数。很明显，这不在他的密码里。@ChrisArena：你可能是对的。很难从这样一个模糊的问题来判断。我认为最好使用SPLIT（），而不是S拆开（“”），因为后者将把''和'\n '添加到列表中，我们不想把它们看成“单词”。split（）使用空格和新行。很好的解释！一个小问题：当（预先）解释

计数器的等效功能时，最好使用
单词not in counts
而不是
not counts.get（word）
。除了更加惯用，在其他（非

计数器）情况下更正确地使用假值之外，它还可以让您更清楚地看到，您正在检查这是一个以前从未见过的新词。@PiotrDabkowski:这一点很好。但是OP发布的输入没有任何新行。如果他的真实输入是这样，我敢打赌它也有标点符号，这意味着我们需要的不仅仅是

str.split

（无论

re.findall

，

re.split

，

str.split

加上

str.translate

，…））谢谢你的解释，谢谢你的解释。很抱歉，我是编程新手：）+1表示排序（计数器（单词））。我已经提供了。这对OP来说并不重要，但这里有一个。可能有些过火了……但任何人有机会学习

groupby

都是一件好事。：）

"As" is repeated 1 time.
"are" is repeated 2 time.
"as" is repeated 3 time.
"certain" is repeated 2 time.
"do" is repeated 1 time.
"far" is repeated 2 time.
"laws" is repeated 1 time.
"mathematics" is repeated 1 time.
"not" is repeated 2 time.
"of" is repeated 1 time.
"reality" is repeated 2 time.
"refer" is repeated 2 time.
"the" is repeated 1 time.
"they" is repeated 3 time.
"to" is repeated 2 time.