I recently had to implement a small check for any variables that might have not been initialized (and their default value is `None`). I came up with this:

```
if None in (var1, var2, var3):
    error_out()

```

While, in my eyes, bordering on beautiful, I was wondering - is this a good way to do it? Is this **the** way to do it? Are there any cases in which this would produce some unexpected results?