如何在python中获取列表值和计数

Question

我正在尝试计算列表中的每个单词。这样我就可以删除具有更大计数值的单词。但是我得到的输出不正确。 假设如果我的文件中有这些行“这是最好的时代，也是最糟糕的时代。这是智慧的时代，这是愚蠢的时代”。我的代码正在做什么打印（是，4）和再次某处（是，3）等等。每次出现单词时，它都会打印该单词，但计数值不同。我需要对每个单词进行一次计数。

for file in files:  
    print(file)
    f=open(file, 'r')
    content = f.read() 
    wordlist = content.split()
    #print(wordlist)
    wordfreq = [wordlist.count(w) for w in wordlist] # a list comprehension
    print("List\n" + str(wordlist) + "\n")
    print("Frequencies\n" + str(wordfreq) + "\n")
    test = [i for i in wordfreq if i > 100]
    print("result\n"+str(list(zip(test,wordlist))))

Answer 1

你可以像这样使用Counter：

>>> from collections import Counter
>>>
>>> s = "it was the best of times it was the worst of times .it was the age of wisdom it was the age of foolishness"
>>>
>>> d = Counter(s.split())
>>> for k,v in d.items():
...     print '{} -> {}'.format(k,v)
...
of -> 4
age -> 2
it -> 3
foolishness -> 1
times -> 2
worst -> 1
.it -> 1
the -> 4
wisdom -> 1
was -> 4
best -> 1
>>>

如果你不想使用collections.Counter，你可以使用这样的字典：

>>> s = "it was the best of times it was the worst of times .it was the age of wisdom it was the age of foolishness"
>>> d = {}
>>> for word in s.split():
...     try:
...         d[word] += 1
...     except KeyError:
...         d[word] = 1
...
>>> d
{'of': 4, 'age': 2, 'it': 3, 'foolishness': 1, 'times': 2, 'worst': 1, '.it': 1, 'the': 4, 'wisdom': 1, 'was': 4, 'best': 1}

Answer 2

没有计数器的解决方案：

new = s.split(' ')
m=list()
for i in new:
 m.append((i , new.count(i)))
for i in set(m):
    print i
del m[:] # deleting list for using it again

输出：

('best', 1)  
('was', 4)   
('times', 2)  
('it', 3)  
('worst', 1)  
('.it', 1)  
('wisdom', 1)  
('foolishness', 1)  
('the', 4)     
('of', 4) 
('age', 2)

another test : 
 s = 'was was it was hello it was'
output :  
('hello', 1)  
('was', 4)  
('it', 2)  

如果您将数据保存到文件中，请使用：

s=""

with open('your-file-name', 'r') as r:
 s+=r.read().replace('\n', '') #reading multi lines

new = s.split(' ')
m=list()
for i in new:
 m.append((i , new.count(i)))
for i in set(m):
    print i
del m[:] # deleting list for using it ag

Answer 3

from collections import Counter

for file in files:
    words = open(file).read().split()
    frequencies = Counter(words)

Answer 4

您可以从collections 使用Counter：

from collections import Counter
import itertools

for file in files:

    data = itertools.chain.from_iterable([i.strip('\n').split() for i in open(file)])

    the_counts = Counter(data)

    print("wordlist: {}".format(data))
    print("frequencies: {}".format(dict(the_count))
    test = [(a, b) for a, b in the_count.items() if b > 100]

Answer 5

import pandas as pd
a = pd.Series(txt.split()).value_counts().reset_index().rename(columns={0:"counts","index":"word"})
a[a.counts<100]