列表理解有两个条件

Question

It's possible to use list comprehension in python with two expression?

IE: I have a list with dots '.' and semicolon ';' and I want to create a boolean list using the first one as a parameter:

• Dot = True
• Semicolon = False

I know how to create using only one expression:

L1 = [True if i == '.' for i in L2]

Or

L1 = [False if i == ';' for i in L2]

It's possible to merge those clausules in one list comprehension?

Edit: [.;.;.] should transform into [True, False, True, False, True]

Answer 1

要另外防止其他字符，请使用：

L1 = [ch == '.' for ch in L2 if ch in '.;']

Answer 2

[char == '.' for char in l]

char == '.' evaluates to True if the character is a period and False otherwise.

If you need a more complex transformation, you can use

mapping = {
    '.': True,
    ';': False,
    ...
}

[mapping[char] for char in l]

If you need to filter out characters other than the ones you're looking for,

[mapping[char] for char in l if char in mapping]