在python中将列表追加到另一个列表

Question

我有一个.txt文件，其中包含如下数据：

math,mathematics
data,machine-learning-model
machine-learning,statistics,unsupervised-learning,books
orange,lda
machine-learning,deep-learning,keras,tensorflow
keras,similarity,distance,features

现在，我想将每一行作为一个列表存储在一个更大的列表中

句子的预期输出如下：

sentences = [['math', 'mathematics'],
['data', 'machine-learning-model'],
['machine-learning', 'statistics', 'unsupervised-learning', 'books'],
['orange', 'lda']]

这就是我所尝试的：

temp_tokens = []
sentences = []

fp  = open('tags.txt')
lines = fp.readlines()
for line in lines:
    temp_tokens.clear()
    for word in line.split(','):
        if word.strip('\n'):
            temp_tokens.append(word)
            temp_tokens = [e.replace('\n','') for e in temp_tokens]
    
    print(temp_tokens)
    sentences.append(temp_tokens)
    

print(sentences)    

现在，当我print(temp_tokens)时，我得到以下输出：

['math', 'mathematics']
['data', 'machine-learning-model']
['machine-learning', 'statistics', 'unsupervised-learning', 'books']
['orange', 'lda']
['machine-learning', 'deep-learning', 'keras', 'tensorflow']
['keras', 'similarity', 'distance', 'features']
['machine-learning']

这很好。但是，单个列表没有正确地附加到列表sentences。当我做的时候。句子列表如下所示：

它只包含每行中的单个标记，而不是作为列表的行本身

[['data'], ['machine-learning'], ['orange'], ['machine-learning'], ['keras'], ['machine-learning\n'], ['machine-learning'], ['dataset'], ['lstm\n'], ['python'], ['python'], ['reinforcement-learning'], ['machine-learning'], ['machine-learning'], ['machine-learning'], ['machine-learning'], ['overfitting'], ['machine-learning'], ['machine-learning'], ['time-series'], ['machine-learning'], ['linear-regression'], ['python'], ['keras'], ['python'], ['python'], ['pytorch\n'], ['machine-learning'], ['machine-learning'], ['machine-learning'], ['machine-learning'], ['gradient-descent\n'], ['python'], ['image'], ['dataset'], ['python'], ['neural-network'], ['machine-learning'], ['feature-selection'], ['nlp'], ['machine-learning'], ['python'], ['machine-learning'], ['cnn'], ['machine-learning'], ['neural-network'], ['machine-learning'], ['machine-learning'], ['deep-learning'], ['machine-learning'], ['python'], ['tensorflow'], ['machine-learning'], ['machine-learning'], ['machine-learning']

有人能告诉我我的代码有什么问题吗？为什么列表“temp_tokens”没有作为一个完整的列表附加到“sentences”上，而只是作为单独的标记

有人能解释一下吗

Answer 1

或者，使用

with open('tags.txt') as fp:
    sentences = [line.strip().split(',') for line in fp]
print(sentences)

Answer 2

这应该起作用：

sentences = []
fp  = open('tags.txt')
for line in fp.readlines():
    temp_tokens = line.strip().split(",")
    sentences.append(temp_tokens)
print(sentences)

或者更干净地说：

sentences = []
with open('tags.txt') as fp:
    for line in fp.readlines():
        sentences.append(line.strip().split(","))
print(sentences)