检查多个变量是否为None的最python化的方法是什么?

If I have a construct like this:

如果我有这样一个构念:

def foo():
    a=None
    b=None
    c=None

    #...loop over a config file or command line options...

    if a is not None and b is not None and c is not None:
        doSomething(a,b,c)
    else:
        print "A config parameter is missing..."

What is the preferred syntax in python to check if all variables are set to useful values? Is it as I have written, or another better way?

python中检查所有变量是否设置为有用值的首选语法是什么?是像我写的那样，还是另一种更好的方式?

This is different from this question: not None test in Python ... I am looking for the preferred method for checking if many conditions are not None. The option I have typed seems very long and non-pythonic.

这与这个问题不同:在Python中不是没有测试…我正在寻找的首选方法，以检查是否有许多条件不是没有。我输入的选项看起来很长而且不是python语言的。

2 个解决方案

#1

There's nothing wrong with the way you're doing it.

你这样做没有错。

If you have a lot of variables, you could put them in a list and use all:

如果你有很多变量，你可以把它们放在一个列表中，然后使用所有的变量:

if all(v is not None for v in [A, B, C, D, E]):

#2

Complementing Daniel Roseman's answer, I think:

补充Daniel Roseman的回答，我认为:

if all([a,b,c,d]):

is cleaner

更清洁

Since all() built-in function already iterates over the list checking for None values

因为all()内置函数已经遍历列表，检查无值

#1