Can anyone spot why this function is returning an empty list?

[hhydration]

def affine_n_encode(text, n, a,b):
    ngraphs=[]
    nums=[]
    texts=[]
    if len(text) % n==0:
        for i in range(len(text)):
            ngraphs.append(text[i:i+n])
        else:
            list(text)
            text.append(['x']*(len(text)%n))
            ''.join(text)
            ngraphs.append(text[i:i+n])
    for n_graph in ngraphs:
        nums.append(convert_to_num(n_graph))
    for num in nums:
        texts.append(convert_to_text(((a*(num)+b)%26),n))
        ''.join(texts)
    return texts
text = "THEQUICKBROWNFOXJUMPEDOVERTHELAZYDOG"
enc = affine_n_encode(text, 5, 347, 1721)

print(enc)

Edit: Please let me know if you need any more information about the function to understand the problem