def replace_characters(main_string, chars, new_string):
    """
    Parameters:
    main_string (str): The string for which you want to make the replacement
    chars (str): The character that you want to replace
    new_string (str): The new string that will replace the previous string (chars)
    
    Return:
    The original string, but with the new characters now incorporated.
    """
    
    for char in chars:
        try :
            if char in main_string:
                main_string = main_string.replace(char, new_string)
        except:
            continue       
    return main_string