Python 通过比较列表和字符串中的值来创建新列表

我有预定义列表中的元素和查询字符串。我想检查

query\u str

在预定义列表中是否有任何值，如果有，将它们作为单独的元素附加到新列表中

predefined_lst = ['hello', 'goodbye', 'see you later']

query_str  = 'hello | are you having a nice day?  see you later |'

new_lst = []

我有将字符串与列表中的值进行比较的语法，但无法将字符串中出现的值作为列表中的单个元素附加到新列表中。 在上面的例子中，

new\u lst

应该是

new\u lst=['hello'，'see you later']

当我打印

new\lst

时，我现在得到的结果就是真的

predefined_lst = ['hello', 'goodbye', 'see you later']
query_str  = 'hello | are you having a nice day?  see you later |'
new_lst = []
match = if any(string in query_str for string in predefined_lst)
new_lst.append(match)
print(new_lst)

---

您已经迷失在列表理解中：

new_lst = [string for string in predefined_lst if string in query_str]

---

当前，您正在将

True

或

False

值附加到行中的

new\lst

match = if any(string in query_str for string in predefined_lst)

这是因为

if…

返回布尔值

True

或

False

相反，试试这个

for x in predefined_list:
    if x in query_str:
        new_list.append(x)

或者作为一个列表comp

new_lst = [string for string in predefined_lst if string in query_str]

您可以使用来通过各种分隔符进行解析：

[i.strip() for i in re.split(r'[?|]',query_str) if i.strip() in predefined_lst]

或：

---

这是一个简单的解决方案：

predefined_lst = ['hello', 'goodbye', 'see you later']
query_str  = 'hello | are you having a nice day?  see you later |'
new_lst = []
for item in predefined_lst:
    if item in query_str:
        new_lst.append(item)
print(new_lst)

---

您正在将比较结果附加到新列表中。您应该追加的是字符串本身

predefined_lst = ['hello', 'goodbye', 'see you later']
query_str  = 'hello | are you having a nice day?  see you later |'
new_lst = []
for str in predefined_lst: 
    if(str in query_str):
        new_lst.append(str)
print new_lst

---

另一种方法是使用

过滤器
：

>>> predefined_lst = ['hello', 'goodbye', 'see you later']
>>> query_str  = 'hello | are you having a nice day?  see you later |'
>>> 
>>> list(filter(lambda s: s in query_str, predefined_lst))
['hello', 'see you later']

“|”在他的字符串中不是一个特殊的符号。它不是分隔符。事实上，带有
if
的那一行是一个语法错误。@kindall已修复。
>>> predefined_lst = ['hello', 'goodbye', 'see you later']
>>> query_str  = 'hello | are you having a nice day?  see you later |'
>>> 
>>> list(filter(lambda s: s in query_str, predefined_lst))
['hello', 'see you later']