Проблема со списком в цикле

all_v = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
all_alph  = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
all=[ ]
cik=0
i=0
while i!=25:
    sdvig=all_alph[cik]
    all_v.remove(sdvig)
    all_v.append(sdvig)
    all.append(all_v)
    cik+=1
    i+=1
print(all)

def form_dict():
    d = {}
    iter_ = 0
    for i in range(0, 127):
        d[iter_] = chr(i)
        iter_ = iter_ + 1
    return d
 
 
def encode_val(word):
    list_code = []
    lent = len(word)
    d = form_dict()
 
    for w in range(lent):
        for value in d:
            if word[w] == d[value]:
                list_code.append(value)
    return list_code
 
 
def comparator(value, key):
    len_key = len(key)
    dic = {}
    iter_ = 0
    full = 0
 
    for i in value:
        dic[full] = [i, key[iter_]]
        full = full + 1
        iter_ = iter_ + 1
        if iter_ >= len_key:
            iter_ = 0
    return dic
 
 
def full_encode(value, key):
    dic = comparator(value, key)
    print("Compare full encode", dic)
    lis = []
    d = form_dict()
 
    for v in dic:
        go = (dic[v][0]+dic[v][1]) % len(d)
        lis.append(go)
    return lis
 
 
def decode_val(list_in):
    list_code = []
    lent = len(list_in)
    d = form_dict()
 
    for i in range(lent):
        for value in d:
            if list_in[i] == value:
                list_code.append(d[value])
    return list_code
 
 
def full_decode(value, key):
    dic = comparator(value, key)
    print("Deshifre=", dic)
    d = form_dict()
    lis = []
 
    for v in dic:
        go = (dic[v][0]-dic[v][1]+len(d)) % len(d)
        lis.append(go)
    return lis
 
 
word = input("Введите строку, которую нужно закодировать: ")
key = input("Введите ключ: ")
key_encoded = encode_val(key)
value_encoded = encode_val(word)
shifre = full_encode(value_encoded, key_encoded)
decoded = full_decode(shifre, key_encoded)
decode_word_list = decode_val(decoded)
 
print("Слово: " + word)
print("Ключ: " + key)
print("Value= ", value_encoded)
print("Key= ", key_encoded)
print("Шифр=", "".join(decode_val(shifre)))
print("Decode list=", decoded)
print("Word=", "".join(decode_word_list))