删除列表中没有子字符串的项目的优雅方式 [英] Elegant way to delete items in a list which do not has substrings that appear in another list

问题描述

最近我遇到了这个问题:

Recently I encountered this problem:

说有一个我要处理的东西的清单:

Say there is a list of something I want to process:

process_list=["/test/fruit/apple","/test/fruit/pineapple","/test/fruit/banana","/test/tech/apple-pen","/test/animal/python","/test/animal/penguin"]

我想使用其他列表排除某些内容，例如:

And I want to exclude something using another list, for instance:

exclude_list=["apple","python"]

在将exclude_list应用于它之后，process_list应该是这样的(任何包含子项的process_list项:

The process_list should be like this after I apply the exclude_list to it( any process_list item that contains a sub:

["/test/fruit/banana","/test/animal/penguin","/test/fruit/pineapple"]

，或者如果exclude_list为: exclude_list=["pen","banana"]

or if the exclude_list is: exclude_list=["pen","banana"]

在应用过滤器后，process_list应该是这样:

The process_list should be this after apply the filter:

["/test/fruit/apple","/test/fruit/pineapple","/test/animal/python"]

所以我最初尝试的是:

for item in exclude_list:
    for name in (process_list):
        if item in name:
            process_list.remove(name)

当然这是行不通的，因为不允许在使用for循环对其进行迭代时从列表中删除元素.该代码只删除了第一个匹配项，然后停止了.

Of course this didn't work because removing elements from the list while iterating over it using a for loop is not permitted. The code only removed the first match and then stopped.

因此，我想出了一种方法来处理另一个列表:

So then I came up a way to do this with another list:

deletion_list=[] #Track names that need to be deleted
for item in exclude_list:
    for name in (process_list):
        if item in name:
            deletion_list.append(name)
# A list comprehension
process_list=[ x for x in process_list if x not in deletion_list ]  

它有效，但是我的胆量告诉我，也许有一种更优雅的方法.现在需要另一个列表来存储需要删除的名称.有什么想法吗?

It works, but my guts tell me there may be a more elegant way. Now it need s another list to store the name need to be deleted. Any ideas?

推荐答案

您可以使用

You may use the list comprehension expression using all() filter as:

# Here: `p` is the entry from `process_list`
#       `e` is the entry from `exclude_list`

>>> [p for p in process_list if all(e not in p for e in exclude_list)]                              
['/test/fruit/banana', '/test/animal/penguin']

---

关于您的声明:

---

Regarding your statement:

当然这是行不通的，因为不允许使用for循环在列表上进行迭代时从列表中删除元素.该代码只删除了第一个匹配项，然后停止了.

Of course this didn't work because removing elements from the list while iterating over it using a for loop is not permitted. The code only removed the first match and then stopped.

您可以按以下方式遍历列表的副本:

You could have iterate over the copy of the list as:

 for item in list(exclude_list):  # OR, for item in exclude_list[:]:
 #              ^-- Creates new copy ----------------------------^           

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