def split_len(seq, length):
return [seq[i:i + length] for i in range(0, len(seq), length)]
def encode(key, plaintext):
order = {
int(val): num for num, val in enumerate(key)
}
ciphertext = ''

for index in sorted(order.keys()):
for part in split_len(plaintext, len(key)):
try:ciphertext += part[order[index]]
except IndexError:
continue
return ciphertext
print(encode('3214', 'HELLO'))