how to upper or lower specified substring??

Question

how to upper or lower specified substring in python with upper() or lower()??

Answer 1

s= "HELLO python"
print( s[:5].lower() )
print( s[6:].upper() )

Answer 2

this mean that every string have a method called upper() for get itself to uppercase, and a method lower() to return itself to lowercase

Answer 3

is that means i cant put any arguments upper("here") ??? like split()