为空元组列表返回False的最佳方法

Question

Sometimes, DB returns list of empty tuples as such [(), (), ()] . I need to set False for this type of return. Here is what I do:

Say:

a = [(), (), ()]
b = all([bool(i) for i in a])
print b
False

Is there a better way?

Answer 1

Actually, you want to use any , not all :

>>> a = [(), (), ()]
>>> b = all(a)
>>> print b
False
>>>

>>> a = [(), (1,), ()]
>>> b = all(a)
>>> print b
False
>>>

>>> a = [(), (), ()]
>>> b = any(a)
>>> print b
False
>>>

>>> a = [(), (1,), ()]
>>> b = any(a)
>>> print b
True
>>>

Notice that all will return False unless every element is "truthy".

You don't need to use bool at all.

Answer 2

使用any()检查是否有非空。

any([(), (), ()])