Functions (2) code_cyclic(index,letter)

Yes, you know this function, but it is required that we take a quick look at it:

def code_cyclic(index, letter):
    '''Cyclic transform of letters based on the index of the letter in the word and
     that in the series of alphabets in order
     Arguments (Parameters, I guess):
     _____________
     index - index of the letter in the word (type : int)
     letter - the letter to be coded (type : str)'''
    # The formula used here is : 26 * (index of the letter in word - 1) + (index of the letter in the alphabets)
    # I had to use a separate variable 'index' to avoid the confusion the program gets when
    # choosing the index of the letter (eg., in the case of "HELLO", there are 2 'L's and this will cause confusion
    # This problem has been solved in the upcoming function.
    return 26 * index + (find_index(letter) + 1)

Sorry for making such clumsy code by adding big comments (instead of short, concise and implicit ones).

Here, we implement the formula referred to in the prologue , but alongside that, we add that missing '1' to the index of the letter to get the correct position value of the letter.

There is a silly reason to why I call this function code_cyclic : since this function is going to be used in a cyclic process and that the value yielded by this function for the same letter varies according to the letter's position in the word (eg. : 'Hello' - here, we have 2 'l's at different positions which alters the value yielded by the function for the letter 'l'). It is also to be noted that I used the find_index function (whose making would sound unnecessary but did indeed work well for me by reducing the amount of time I used to make this code)