In the exercise given in the title of is_prime I tried to follow the instruction and get the result right. However I didn't understand the code for the loop. Can someone explain it to me why we needed to limit the rage from 2 and x-1. In particular this part of the code

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

```
def is_prime(x):
if x < 2:
return False
else:
for n in range(2,x-1):
if x % n == 0:
return False
else:
return True
x = raw_input("Is prime number?")
print is_prime(int(x))
Thanks you, that would be a great help.
```