2、数据类型转化

#数据类型转化
# str -----> list    .split()
# list-----> str   ''.join(list)
# tuple----->list   list(tuple)
# list----->tuple   tuple(list)
# dic----->list   list(dic)  #列表中的元素只有key

# tu1 = (1, 2, 3)
# l1 = list(tu1)
# print(l1)
# tu2 = tuple(l1)
# print(tu2)

# dic = {'k1': 'v1', 'k2': 'v2','k3': 'v3',}
# l1 = list(dic)
# print(l1)
# print(list(dic.keys()))
# print(list(dic.values()))
# print(list(dic.items()))