HackerRank sWAP cASE problem solution in python

In this Hackerrank sWAP cASE problem solution in python, we need to develop a program that can take a string as input, and then we need to convert all the lowercase letters of that string into uppercase and uppercase to lowercase.

Problem solution in Python 2 programming.

# Enter your code here. Read input from STDIN. Print output to STDOUT
name = raw_input()
print ''.join(c.lower() if c.isupper() else c.upper() for c in name)

Problem solution in Python 3 programming.

def swap_case(s):
    return s.swapcase()

Problem solution in pypy programming.

def swap_case(s):
    res = ''
    for ch in s:
        if ch.isupper():
            res += ch.lower()
        else:
            res += ch.upper()
    return res

Problem solution in pypy3 programming.

def swap_case(s):
    result = []
    for letter in s:
        if letter == letter.lower():
            result.append(letter.upper())
        elif letter == letter.upper():
            result.append(letter.lower())
        else:
            result.append(letter)
    return ''.join(result)