Hi,

here’s my code:

```
def is_prime(x):
for n in range(x, 2, x-1):
if x % n == 0 and n != x and n != 1 and n != 0:
return True
else:
return False
```

That’s the error message:

**Your function fails on is_prime(0). It returns None when it should return False.**

I do not understand what’s wrong with the code.

Can you explain me?

Thanks in advance!

CR