Solution Exercise 55: swapping a given string without using the swapcase method en python

Exercise 55

Write a python program as a function which takes as parameters a string s and which returns a string obtained from the string s by transforming each uppercase character into a lowercase character and vice versa without using the swapcase() method. Example if s = "Hello Wordls!" , the function returns the string "hELLO wORLD!"

Solution

def mySwapcase(s):
    
    # initializing the swapped string
    s_swap = ""
    
    # iterate over all characters of s 
    #and testing if the character is in uppercase or lowercase
    for x in s:
        if x.isupper():
            
            # swapping the character
            x = x.lower()
            s_swap = s_swap + x
        elif  x.islower():
            # swapping the character
            x = x.upper()
            s_swap = s_swap + x
        else:
            s_swap = s_swap + x
            
    return s_swap

# test and display result
print(mySwapcase("Hello World !")) # The output is : hELLO wORLD !