如何在python中为一个if语句设置多个条件
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How to have multiple conditions for one if statement in python
提问by SooBaccaCole
So I am writing some code in python 3.1.5 that requires there be more than one condition for something to happen. Example:
所以我在 python 3.1.5 中编写了一些代码，需要有多个条件才能发生。例子：
def example(arg1, arg2, arg3):
if arg1 == 1:
if arg2 == 2:
if arg3 == 3:
print("Example Text")
The problem is that when I do this it doesn't print anything if arg2 and arg3 are equal to anything but 0. Help?
问题是，当我这样做时，如果 arg2 和 arg3 等于 0 以外的任何值，它就不会打印任何内容。有帮助吗？
回答by SSung2710
I would use
我会用
def example(arg1, arg2, arg3):
if arg1 == 1 and arg2 == 2 and arg3 == 3:
print("Example Text")
The andoperator is identical to the logic gate with the same name; it will return 1 if and only if all of the inputs are 1. You can also use oroperator if you want that logic gate.
的and操作者是相同的具有相同名称的逻辑门; 当且仅当所有输入为 1 时，它才会返回 1。or如果需要该逻辑门，也可以使用运算符。
EDIT: Actually, the code provided in your post works fine with me. I don't see any problems with that. I think that this might be a problem with your Python, not the actual language.
编辑：实际上，您帖子中提供的代码对我来说很好用。我不认为这有任何问题。我认为这可能是您的 Python 的问题，而不是实际语言的问题。
回答by burkesquires
Darian Moody has a nice solution to this challenge in his blog post:
Darian Moody 在他的博文中为这个挑战提供了一个很好的解决方案：
a = 1
b = 2
c = True
rules = [a == 1,
b == 2,
c == True]
if all(rules):
print("Success!")
The all() method returns Truewhen all elements in the given iterable are true. If not, it returns False.
True当给定迭代中的所有元素都为真时，all() 方法返回。如果不是，则返回False。
You can read a littlemore about it in the python docs hereand more information and examples here.
你可以阅读一点点在Python文档更多关于它在这里和更多的信息和例子在这里。
(I also answered the similar question with this info here - How to have multiple conditions for one if statement in python)
（我也在这里用这个信息回答了类似的问题 - How to have multiple conditions for one if statement in python）
回答by Elyria
Might be a bit odd or bad practice but this is one way of going about it.
可能有点奇怪或不好的做法，但这是一种解决方法。
(arg1, arg2, arg3) = (1, 2, 3)
if (arg1 == 1)*(arg2 == 2)*(arg3 == 3):
print('Example.')
Anything multiplied by 0 == 0. If any of these conditions fail then it evaluates to false.
任何乘以 0 == 0 的值。如果这些条件中的任何一个失败，那么它的计算结果为 false。
回答by Christian Henry
Assuming you're passing in strings rather than integers, try casting the arguments to integers:
假设您传入的是字符串而不是整数，请尝试将参数转换为整数：
def example(arg1, arg2, arg3):
if int(arg1) == 1 and int(arg2) == 2 and int(arg3) == 3:
print("Example Text")
(Edited to emphasize I'm not asking for clarification; I was trying to be diplomatic in my answer. )
（编辑以强调我不是在要求澄清；我试图在我的回答中保持外交关系。）
回答by no nein
I am a little late to the party but I thought I'd share a way of doing it, if you have identical types of conditions, i.e. checking if all, any or at given amount of A_1=A_2 and B_1=B_2, this can be done in the following way:
我参加聚会有点晚了，但我想我会分享一种方法，如果您有相同类型的条件，即检查是否所有、任何或给定数量的 A_1=A_2 和 B_1=B_2，这可以通过以下方式完成：
cond_list_1=["1","2","3"]
cond_list_2=["3","2","1"]
nr_conds=1
if len([True for i, j in zip(cond_list_1, cond_list_2) if i == j])>=nr_conds:
print("At least " + str(nr_conds) + " conditions are fullfilled")
if len([True for i, j in zip(cond_list_1, cond_list_2) if i == j])==len(cond_list_1):
print("All conditions are fullfilled")
This means you can just change in the two initial lists, at least for me this makes it easier.
这意味着您可以更改两个初始列表，至少对我来说这更容易。
