怎么使用snowNLP对.txt文件里的评论进行情感分析python

使用 `snowNLP` 进行情感分析需要先安装该库，可以使用 `pip` 进行安装：

pip install snownlp

下面是对 `.txt` 文件进行情感分析的步骤：

1. 导入 `snownlp` 库和打开 `.txt` 文件：

import codecs
from snownlp import SnowNLP

with codecs.open('comments.txt', 'r', encoding='utf-8') as f:
    comments = f.readlines()

2. 对每条评论进行情感分析，统计正面和负面评论的数量：

n_positive = 0
n_negative = 0

for comment in comments:
    s = SnowNLP(comment)
    if s.sentiments > 0.5:
        n_positive += 1
    else:
        n_negative += 1

3. 计算正面评论和负面评论的比例：

positive_ratio = n_positive / len(comments)
negative_ratio = n_negative / len(comments)

print('正面评论比例：{:.2%}'.format(positive_ratio))
print('负面评论比例：{:.2%}'.format(negative_ratio))

完整代码如下：

import codecs
from snownlp import SnowNLP

with codecs.open('comments.txt', 'r', encoding='utf-8') as f:
    comments = f.readlines()

n_positive = 0
n_negative = 0

for comment in comments:
    s = SnowNLP(comment)
    if s.sentiments > 0.5:
        n_positive += 1
    else:
        n_negative += 1

positive_ratio = n_positive / len(comments)
negative_ratio = n_negative / len(comments)

print('正面评论比例：{:.2%}'.format(positive_ratio))
print('负面评论比例：{:.2%}'.format(negative_ratio))