any idea how sort list contains elements of type set ? code i'm using: sorted_by_second = sorted(result_list, key=lambda set: set[1]) example of how result_list looks like: [['past due', '32.86691794423967'], ['code', '23.24240338748313'], ['why:customer','27.65754595407057']] i sort list descending order according 2nd element in each tupple of list elements. sorted list result should like [['past due', '32.86691794423967'], ['why:customer','27.65754595407057'], ['code', '23.24240338748313']] i suggest use float map second element string number. allow sorted sort numbers. if don't use float , sorted sort second element strings. sorted(result_list, key=lambda x: float(x[1]), reverse=true) result: [['past due', '32.86691794423967'], ['why:customer', '27.65754595407057'], ['code', '23.24240338748313']] ...