This is a follow up from my kata The old switcheroo
Write
```python
def encode(str)
```
that takes in a string ```str``` and replaces all the letters with their respective positions in the English alphabet.
```python
encode('abc') == '123'   # a is 1st in English alpabet, b is 2nd and c is 3rd
encode('codewars') == '315452311819'
encode('abc-#@5') == '123-#@5'
```
String are case sensitive.
def encode(s):
    return ''.join(str(ord(x) - ord('a') + 1) if x.isalpha() else x for x in s.lower())
def encode(s):
    return ''.join(str(ord(x) - ord('a') + 1) if x.isalpha() else x for x in s.lower())