case change in python code example

Example 1: converting capital letters to lowercase and viceversa in python

s=input()
new_str=""
for i in range (len(s)):
    if s[i].isupper():
        new_str+=s[i].lower()
    elif s[i].islower():
        new_str+=s[i].upper()
    else:
        new_str+=s[i]
print(new_str)

Example 2: python string to lower

str = 'heLLo WorLD'
print(str.lower())
# hello world

Example 3: how to convert uppercase to lowercase and vice versa in python

def swap_string():
	s=input()
	swapped_string=""
	swapped_string+=s.swapcase()
    return swapped_string