python - 从包含某些关键字的列表中删除多个字符串元素

Question

我有一个名为文件的列表，由字符串元素组成:

files = ['Upside Your Head.txt', 'The Mighty Quinn - [Remastered].txt', 'The Mighty Quinn - (live).txt', 'Fixin To Die (Mono version).txt', '10,000 Men - [Remastered].txt', '10,000 Men.txt', '10.000 Men - (live).txt']

我正在尝试删除包含特定关键字的元素(例如 Live、Remastered、Mono)。我写的代码是这样的:

files = [i for i in files if '(Live)' not in i]
files = [i for i in files if '[Remastered]' not in i]
files = [i for i in files if '(Mono' not in i]

将上述所有三行都包含在一个语句中的更好做法是什么？考虑到我想稍后添加更多关键字。

Answer 1

概括这一点的第一步是将多个条件与逻辑运算符结合起来:

files = [i for i in files if '(Live)' not in i]
files = [i for i in files if '[Remastered]' not in i]
files = [i for i in files if '(Mono' not in i]

成为

files = [
    i for i in files
    if (
        '(Live)' not in i
        and '[Remastered]' not in i
        and '(Mono' not in i
    )
]

或者，通过 De Morgan's laws ,

files = [
    i for i in files
    if not (
        '(Live)' in i
        or '[Remastered]' in i
        or '(Mono' in i
    )
]

现在，为了能够从预定义列表中获取关键字并相应地自动调整条件数量，我们可以使用内置的 all或 any功能:

• a and b and c可以替换为all([a, b, c])
• a or b or c 可以替换为 any([a, b, c])

(参见:How to apply a logical operator to all elements in a python list)

除了列表，我们还可以将生成器表达式传递给all 和any。

因此，条件

if (
    '(Live)' not in i
    and '[Remastered]' not in i
    and '(Mono' not in i
)

可以写成

if all(keyword not in i for keyword in ['(Live)', '[Remastered]', '(Mono'])

和

if not (
    '(Live)' in i
    or '[Remastered]' in i
    or '(Mono' in i
)

作为

if not any(keyword in i for keyword in ['(Live)', '[Remastered]', '(Mono'])

结果，代码可以变成

keywords = ['(Live)', '[Remastered]', '(Mono']
files = [i for i in files if all(keyword not in i for keyword in keywords)]

或

keywords = ['(Live)', '[Remastered]', '(Mono']
files = [i for i in files if not any(keyword in i for keyword in keywords)]