Функция возвращающая словарь из списков

#-*- coding: utf-8 -*-
from itertools import zip_longest #
 
def func(a:list, b:list)->dict:
    """
    function returning a dictionary
    """
    c = []
    for i in a:
        if i not in c:
            c.append(i)
 
    if len(b)>len(c):
        d = []
        for j in range(len(c)):
            d.append(j)
 
    return print(dict(zip_longest(c, d)))
 
if __name__ =='__main__':
    func(['a', 'b', 'd', 'd', 'e'],[1, 2, 3, 4, 5, 6 ])

from itertools import zip_longest #
 
def func(a:list, b:list)->dict:
    """
    function returning a dictionary
    """
    c = []
    for i in a:
        if i not in c:
            c.append(i)
 
    d = []
    if len(b)>len(c):
        for j in range(len(c)):
            d.append(j)
    else:
        for k in range(len(b)):
            d.append(k)
 
    return print(dict(zip_longest(c, d)))
 
if __name__ =='__main__':
    func(['a', 'b', 'c', 'd'],[1, 2 , 3])
    func(['a', 'b', 'c', 'd', 'e'],[1, 2 ])
    func(['a', 'b', 'd', 'd', 'e'],[1, 2 ])
    func(['a', 'b', 'd', 'd', 'e'],[1, 2, 3, 4, 5, 6 ])

result = func(['a', 'b', 'c', 'd'],[1, 2 , 3])
print(result)
assert result == {'a': 0, 'b': 1, 'c': 2, 'd': None}

def func(a:list, b:list)->dict:
    for _ in range(len(a) - len(b)):
        b.append(None)
 
    c = {}
    for key, val in zip(a,b):
        c.setdefault(key, val)
    return c
 
if __name__ =='__main__':
 
    print(func(['a', 'b', 'c', 'd', 'e'],[1, 2, 3, 4, 5, 6 ]))
    print(func(['a', 'b', 'c', 'd', 'e','f','g','h'],[1, 2, 3, 4, 5, 6 ]))

print(func(['a', 'b', 'c', 'd'],[1, 2, 3, 4, 5, 6 ]))

{'a': 1, 'b': 2, 'c': 3, 'd': 4}