一行用于在Python中将元素添加到列表的循环

Question

我正在尝试从数据集中删除停用词（从nltk），但是不确定为什么单行查询不起作用：

filtered_words = [word if word not in stop_words for word in words]

这是我需要做的：

filtered_words = []
for word in words:
    if word not in stop_words:
        filtered_words.append(word)

Answer 1

如果必须在列表理解的末尾：

filtered_words = [word for word in words if word not in stop_words]

请参阅：https://www.pythonforbeginners.com/basics/list-comprehensions-in-python

Answer 2

您想要的语法是：

x = [x for x in range(200) if x%3 == 0 ]

为

添加条件

您使用的语法还需要其他类似的内容：

x = [x if x%3 == 0  else None for x in range(200)  ]

这会产生错误：

x = [x if x%3 == 0  for x in range(200)  ]

Answer 3

语法是向后的。 [如果单词不在stop_words中，则在start_words中添加单词的单词]

---

starting_words = ["hi", "joshing", "afflate", "damage"]
stop_words = ["afflate", "K", "books"]
filtered_words = []
'''for word in starting_words:
    if word not in stop_words:
        filtered_words.append(word)
==

filtered_words = [word for word in starting_words if word not in stop_words]'''