1. upper
2. lower
>>> string="heLLO"
>>> string.upper()
'HELLO'
>>> string.lower()
'hello'
>>> string[0].upper()+string[1:].lower()
'Hello'
3. capitalize
>>> li = "this is a good cup!"
>>> li.capitalize()
'This is a good cup!'
4. title
>>> li = "this is a good cup!"
>>> li.title()
'This Is A Good Cup!'