def change_int_to_str(lst, idx_to_change, letter_to_add):
    """
    Change a column of ints to a column of strings by adding a letter. This is used to 'fool' the
    neural network into thinking that a number is a string.
    =Parameters=
    lst: The list containing your dataset.
    idx_to_change: List containing the indices of the columns that you want to transform.
    letter_to_add: String with the letter that you want to insert into each item.
    """
    
    new_lst = []
    for item in lst:
        for idx in idx_to_change:
            item[idx] = letter_to_add + item[idx]
        new_lst.append(item)
        
    return new_lst