Question

如何计算单词出现在字符串列表中的次数？

例如：

['This is a sentence', 'This is another sentence']

，单词“sentence”的结果为2

Answer 1

使用collections.Counter()对象并在空白处分割单词。你可能也希望小写你的单词，并删除标点符号：

from collections import Counter

counts = Counter()

for sentence in sequence_of_sentences:
    counts.update(word.strip('.,?!"\'').lower() for word in sentence.split())

或者可能使用仅匹配单词字符的正则表达式：

from collections import Counter
import re

counts = Counter()
words = re.compile(r'\w+')

for sentence in sequence_of_sentences:
    counts.update(words.findall(sentence.lower()))

现在你有一个counts字典，包含每个字数。

演示：

>>> sequence_of_sentences = ['This is a sentence', 'This is another sentence']
>>> from collections import Counter
>>> counts = Counter()
>>> for sentence in sequence_of_sentences:
...     counts.update(word.strip('.,?!"\'').lower() for word in sentence.split())
... 
>>> counts
Counter({'this': 2, 'is': 2, 'sentence': 2, 'a': 1, 'another': 1})
>>> counts['sentence']
2

Answer 2

您可以使用一些正则表达式和字典轻松地完成您想要的任务。

import re

dict = {}
sentence_list = ['This is a sentence', 'This is a sentence']
for sentence in sentence_list:
    for word in re.split('\s', sentence): # split with whitespace
        try:
            dict[word] += 1
        except KeyError:
            dict[word] = 1
print dict

计算字符串列表中的单词出现次数

2 个答案: