是否有一种方法可以否定返回给变量的布尔值?

I have a Django site, with an Item object that has a boolean property active. I would like to do something like this to toggle the property from False to True and vice-versa:

我有一个Django站点，其中包含一个具有布尔属性活动的项对象。我想做这样的事情，将属性从False切换到True，反之亦然:

def toggle_active(item_id):
    item = Item.objects.get(id=item_id)
    item.active = !item.active
    item.save()

This syntax is valid in many C-based languages, but seems invalid in Python. Is there another way to do this WITHOUT using:

这种语法在许多基于c的语言中都是有效的，但在Python中似乎是无效的。有没有另一种方法可以不用:

if item.active:
    item.active = False
else:
    item.active = True
item.save()

The native python neg() method seems to return the negation of an integer, not the negation of a boolean.

本机python neg()方法似乎返回整数的否定，而不是布尔值的否定。

Thanks for the help.

谢谢你的帮助。

6 个解决方案

#1

You can do this:

你可以这样做:

item.active = not item.active

That should do the trick :)

这应该可以达到目的:

#2

I think you want

我认为你想要的

item.active = not item.active

#3

item.active = not item.active is the pythonic way

项。主动=不项目。主动是勾股定理

#4

Another (less ~~concise~~ readable, more arithmetic) way to do it would be:

另一种(不那么简明、可读、更算数)的方法是:

item.active = bool(1 - item.active)

#5

The negation for booleans is not.

布尔人的否定是否定的。

def toggle_active(item_id):
    item = Item.objects.get(id=item_id)
    item.active = not item.active
    item.save()

Thanks guys, that was a lightning fast response!

谢谢大家，这是一个闪电般的快速反应!

#6

Its simple to do :

很简单:

item.active = not item.active

So, finally you will end up with :

最后你会得到:

def toggleActive(item_id):
    item = Item.objects.get(id=item_id)
    item.active = not item.active
    item.save()

#1