从 Python 3.x 中的另一个列表中删除单独的项目列表

Question

我有一个列表，其中包含许多标记的二元组。一些二元组未正确标记，因此我想将它们从主列表中删除。 bigrams 的一个词经常重复，所以如果它包含 xyz 词，我可以删除它。伪示例如下：

master_list = ['this is', 'is a', 'a sample', 'sample word', 'sample text', 'this book', 'a car', 'literary text', 'new book', 'them about', 'on the' , 'in that', 'tagged corpus', 'on top', 'a car', 'an orange', 'the book', 'them what', 'then how']

unwanted_words = ['this', 'is', 'a', 'on', 'in', 'an', 'the', 'them']

new_list = [item for item in master_list if not [x for x in unwanted_words] in item]

我可以单独删除项目，即每次我创建一个列表并删除包含单词的项目，比如，'on'。这很乏味，并且需要数小时的过滤和创建新列表来过滤每个不需要的单词。我认为循环会有所帮助。但是，我收到以下类型错误：

Traceback (most recent call last):
File "<pyshell#21>", line 1, in <module>
new_list = [item for item in master_list if not [x for x in  unwanted_words] in item]
File "<pyshell#21>", line 1, in <listcomp>
new_list = [item for item in master_list if not [x for x in unwanted_words] in item]
TypeError: 'in <string>' requires string as left operand, not list

非常感谢您的帮助！

Answer 1

您的条件if not [x for x in unwanted_words] in item 与if not unwanted_words in item 相同，即您正在检查 list 是否包含在 string 中。

相反，您可以使用any 检查二元组的任何部分是否在unwanted_words 中。此外，您可以将 unwanted_words 设为 set 以加快查找速度。

>>> master_list = ['this is', 'is a', 'a sample', 'sample word', 'sample text', 'this book', 'a car', 'literary text', 'new book', 'them about', 'on the' , 'in that', 'tagged corpus', 'on top', 'a car', 'an orange', 'the book', 'them what', 'then how']
>>> unwanted_words = set(['this', 'is', 'a', 'on', 'in', 'an', 'the', 'them'])
>>> [item for item in master_list if not any(x in unwanted_words for x in item.split())]
['sample word', 'sample text', 'literary text', 'new book', 'tagged corpus', 'then how']