Python - bucle y lista

response = {}

for element in [x + 1 for x in range(500)]:

    times = 0

    for i in arr:

        if i == element: times += 1

    response[element] = times

res = sorted(response.items(), key = lambda item: item[1], reverse = True)

for i in range(20): print(f"{res[i][0]} -> {res[i][1]}")