def autocomplete(i, d):
    p = 'qwertyuiopasdfghjklzxcvbnm'
    t = ''.join([x for x in i if x.lower() in p])
    q = [
    w for w in d
    if t in w[:len(t)].lower()
    ]
    if len(q)<=5:
        return q
    else:
        return q[:5]


    print(autocomplete('a3i',[ 'abnormal', 'arm-wrestling', 'absolute',
    'airplane', 'airport', 'amazing', 'apple', 'ball' ]))

q = [w for w in d if t in w[:len(t)].lower() and len(q)< 5]

import string

def autocomplete(i, d, threshold=5):
    i = i.casefold()
    t = ''.join([x for x in i if x in string.ascii_lowercase])
    return [w for cnt,w in enumerate(d) if w.casefold().startswith(t) and cnt < threshold]

import re

def autocomplete(i, d, threshold=5):
    t = re.sub('[^a-z]', '', i.casefold())
    return [w for cnt,w in enumerate(d) if w.casefold().startswith(t) and cnt < threshold]