Why is my string empty?

[karabakh]

Hi,

I want to create a loop that would attach the ids from a certain dictionary to a string, space between ids.

import string

letters = list(string.ascii_lowercase)

dic = {}
lista = []
strin=()
final=[]
for id, i in enumerate(letters):
    dic[id]=i

def alphabet_position(text):
    for i in text:
           strin=' '.join([str(k+1)+v for k,v in dic.items() if v == i.lower()])

But the 'strin' returned is empty. It works fine when I remove the condition in the list comprehension (if v==i.lower())).

Why? Thank you