[Check-IO] Frequency Sorting

Problem: py.checkio.org/en/mission/frequency-sorting/
My Solution

def frequency_sorting(numbers):
    
    # eliminating duplication of elements in a list, "numbers" 
    # then, sorting its list in ascending order
    set_list = sorted(list(set(numbers)))
    # count the number of each elements in "numbers"  
    count = list(map(lambda x: numbers.count(x), set_list))    

    sorted_set_list = sorted(set_list, key=(lambda x: count[set_list.index(x)]), reverse=True)
    sorted_count = sorted(count, reverse = True)

    dummy_list = [] 
    for ele, counts in list(zip(sorted_set_list, sorted_count)):
        dummy_list.extend([ele] * counts)

    return dummy_list

 

Good Solution that I see 

def checkio(numbers):
    return sorted(sorted(numbers), key=numbers.count, reverse=True)