shpping_catalog = {
    'food':{
        'fish':['delisious','aaaa'],
        'meat':['oil','bbbb'],
        'fruit':['fresh','cccc'],
        'vegetables':['healthy','dddd']
    },
    'drink':{
        'milk':['good','eeee']
    },
    'play':{
        'football':['great','ffff','gggg']
    }
}
shpping_catalog['play']['football'][2] = 'hhhh'
print(shpping_catalog)
print(shpping_catalog.values())
print(shpping_catalog.keys())
shpping_catalog.setdefault('work',{'pen':['black','red']})#取不到work，增加一个key，value，取得到就是原来的值
print(shpping_catalog)