Descirtioon regarding expected behavior with floats needs to be clarified

Please use backticks to format code:

```python
def my_hello_world():
  print "Hello world!"
```

That being said, Codewars uses Python 2, not Python 3. In Python 2, range actually creates a list, whereas in version 3 range acts the same as Python 2's xrange. Use the latter to get rid of the memory error.