I’m stuck. This is what I have:

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

I’m stuck. This is what I have:

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

Your function fails on is_prime(2). It returns None when it should return True.

None indicates the absence of a return value, so for `x=2`

, we don’t get a return value. Which return value did you expect? And why doesn’t your code get there?