• Source 
    1. input_text = "Hello World!"
    2. output_text = ""
    3.  
    4. from_map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
    5. to_map   = "NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm"
    6.  
    7. for character in input_text:
    8.  
    9.   search_index = 0
    10.  
    11.   while search_index < len(from_map) and character != from_map[search_index]:
    12.     search_index = search_index + 1
    13.  
    14.   if search_index == len(from_map):
    15.     output_text = output_text + character
    16.   else:
    17.     output_text = output_text + to_map[search_index]
    18.  
    19. print(output_text)
    20. # your code goes here