Python - problemas con ejercicios

def e3():

    o=input("Denota oracion: ")

    caract = list(set(o.replace(" ","")))

    d = dict()

    temp = []

    for car in caract:

        for plb in o.split():

            if car in plb:

                temp.append(plb)

        d[car] = max(temp)

        temp = []

    return d

def e3():

    words = input("Defina oracion: ")

    list_words = words.split(' ')

    d = {}

    for word in list(set(words.replace(' ', ''))):

        str_f = ''

        for item in list_words:

            if word in item:

                if item.count(word) > str_f.count(word):

                    str_f = item

        d[word] = str_f

    return d

print (e3())