Python - 查找文本文件中单词列表的单词频率

Question

我正在努力加快我的项目计算单词频率.我有360多个文本文件,我需要获得单词总数和来自另一个单词列表的每个单词出现的次数.我知道如何使用单个文本文件执行此操作.

>>> import nltk
>>> import os
>>> os.chdir("C:\Users\Cameron\Desktop\PDF-to-txt")
>>> filename="1976.03.txt"
>>> textfile=open(filename,"r")
>>> inputString=textfile.read()
>>> word_list=re.split('\s+',file(filename).read().lower())
>>> print 'Words in text:', len(word_list)
#spits out number of words in the textfile
>>> word_list.count('inflation')
#spits out number of times 'inflation' occurs in the textfile
>>>word_list.count('jobs')
>>>word_list.count('output')

让"通货膨胀","就业","产出"的个人频率变得过于繁琐.我可以将这些单词放入列表中,同时查找列表中所有单词的频率吗？基本上这用Python.

示例:而不是:

>>> word_list.count('inflation')
3
>>> word_list.count('jobs')
5
>>> word_list.count('output')
1

我想这样做(我知道这不是真正的代码,这是我要求帮助的):

>>> list1='inflation', 'jobs', 'output'
>>>word_list.count(list1)
'inflation', 'jobs', 'output'
3, 5, 1

我的单词列表将有10-20个术语,所以我需要能够将Python指向单词列表以获得计数.如果输出能够复制+粘贴到excel电子表格中,并且单词为列,频率为行,那也很好

例:

inflation, jobs, output
3, 5, 1

最后,任何人都可以帮助自动化所有文本文件吗？我想我只是将Python指向文件夹,它可以从新列表中为每个360+文本文件计算上述字数.看起来很简单,但我有点卡住了.有帮助吗？

像这样的输出会很棒:Filename1通胀,工作,输出3,5,1

Filename2
inflation, jobs, output
7, 2, 4

Filename3
inflation, jobs, output
9, 3, 5

谢谢!

Answer 1

collections.Counter()如果我理解你的问题就有这个问题.

文档中的示例似乎与您的问题相符.

# Tally occurrences of words in a list
cnt = Counter()
for word in ['red', 'blue', 'red', 'green', 'blue', 'blue']:
    cnt[word] += 1
print cnt


# Find the ten most common words in Hamlet
import re
words = re.findall('\w+', open('hamlet.txt').read().lower())
Counter(words).most_common(10)

从上面的例子中你应该能够做到:

import re
import collections
words = re.findall('\w+', open('1976.03.txt').read().lower())
print collections.Counter(words)

编辑天真的方法来展示一种方式.

wanted = "fish chips steak"
cnt = Counter()
words = re.findall('\w+', open('1976.03.txt').read().lower())
for word in words:
    if word in wanted:
        cnt[word] += 1
print cnt

Answer 2

一种可能的实现（使用计数器）...

我认为写入 csv 文件并将其导入 Excel 会更简单，而不是打印输出。查看http://docs.python.org/2/library/csv.html并替换print_summary.

import os
from collections import Counter
import glob

def word_frequency(fileobj, words):
    """Build a Counter of specified words in fileobj"""
    # initialise the counter to 0 for each word
    ct = Counter(dict((w, 0) for w in words))
    file_words = (word for line in fileobj for word in line.split())
    filtered_words = (word for word in file_words if word in words)
    return Counter(filtered_words)


def count_words_in_dir(dirpath, words, action=None):
    """For each .txt file in a dir, count the specified words"""
    for filepath in glob.iglob(os.path.join(dirpath, '*.txt')):
        with open(filepath) as f:
            ct = word_frequency(f, words)
            if action:
                action(filepath, ct)


def print_summary(filepath, ct):
    words = sorted(ct.keys())
    counts = [str(ct[k]) for k in words]
    print('{0}\n{1}\n{2}\n\n'.format(
        filepath,
        ', '.join(words),
        ', '.join(counts)))


words = set(['inflation', 'jobs', 'output'])
count_words_in_dir('./', words, action=print_summary)