Check if one of all variables is empty

Question

``` def ask(): global name, loca print "What's your name?" name = raw_input('> ') print "Where are you from?" loca = raw_input('> ') if name or loca == None: print "Please enter valid details." ask() ask() print "Alright, so you're " + name + ", from " + loca + "." ``` With this script, it will only ever print the last line if both of my variables are empty. If I fill in one, or both, it triggers that `if`, making me redo the function. What am I doing wrong here?

Accepted Answer

You have very well isolated the problem:

```
if name or loca == None:
```

Here you think it says:

```
"If either name or loca equal none:"
```

But instead it says:

```
"if (name) is true or (loca equals None) is true:"
```

Where it should say:

```
"if (name equals none) is true or (loca equals none) is true:"
```

Which is:

```
if name is None or loca is None:
```

See, by the way, that None comparisons are better carried out with `is`, since there is only one `None` object.

Also, a more pythonic way of doing it is:

```
if not all((name, loca)):
```

Or, seeing as "all" it's just 2 variables:

```
if not (name and loca):
```

If you don't understand, read around a bit (the Python tutorial is excellent -- go for the conditionals part). Good luck!

Check if one of all variables is empty

Solution

Problem