복수의 DataFrame들을 수직방향으로 통합하기
population_dict = { 'California': 39538223, 'Texas': 29145505, 'Florida': 21538187, 'New York': 20201249, 'Pennsylvania': 13002700 }population1 = pd.Series(population_dict)population_list = [39538223, 29145505, 21538187, 20201249, 13002700]population2 = pd.Series( population..