检查对象列表是否包含具有特定属性值的对象 [英] Check if list of objects contain an object with a certain attribute value
问题描述
我想检查我的对象列表是否包含具有特定属性值的对象.
I want to check if my list of objects contain an object with a certain attribute value.
class Test:
def __init__(self, name):
self.name = name
# in main()
l = []
l.append(Test("t1"))
l.append(Test("t2"))
l.append(Test("t2"))
例如,我想要一种检查列表是否包含名称为"t1"
的对象的方法.怎么做到呢?我发现 https://stackoverflow.com/a/598415/292291 ,
I want a way of checking if list contains an object with name "t1"
for example. How can it be done? I found https://stackoverflow.com/a/598415/292291,
[x for x in myList if x.n == 30] # list of all matches
any(x.n == 30 for x in myList) # if there is any matches
[i for i,x in enumerate(myList) if x.n == 30] # indices of all matches
def first(iterable, default=None):
for item in iterable:
return item
return default
first(x for x in myList if x.n == 30) # the first match, if any
我不想每次都遍历整个列表,我只需要知道是否有1个匹配的实例即可. first(...)
或any(...)
或其他方式可以做到吗?
I don't want to go through the whole list every time, I just need to know if there's 1 instance which matches. Will first(...)
or any(...)
or something else do that?
推荐答案
As you can easily see from the documentation, the any()
function short-circuits an returns True
as soon as a match has been found.
any(x.name == "t2" for x in l)
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