Python基础(字典)

#创造和访问字典
'''
字典是映射类型,元组和列表是序列类型
语法:字典名={关键字:值}
'''
brand={"资产类别":"华为类别","品牌":"","报废方式":"","部门管理":""}
print("资产类别",brand["资产类别"])#资产类别 华为类别
#更换value
brand["资产类别"]="难搞"
print(brand)#{'部门管理': '无', '资产类别': '难搞', '报废方式': '借', '品牌': '空'}
brand=((("2","3"),("4",5)))#将元组作为参数
print(brand)#(('2', '3'), ('4', 5))
#字典的内嵌方法
'''
fromkeys(键值,值)
'''
zidian={}
print(zidian.fromkeys((1,2,3),"number"))#{1: 'number', 2: 'number', 3: 'number'}
print(zidian.fromkeys((1,2,3),("number","two")))#{1: ('number', 'two'), 2: ('number', 'two'), 3: ('number', 'two')}
print(zidian.fromkeys((1,2,3)))#{1: None, 2: None, 3: None}
brand={"资产类别":"华为类别","品牌":"","报废方式":"","部门管理":""}
#循环打印纸值
for eachvalue in brand.values():
    print(eachvalue)
#循环打印keys
for eachkeys in brand.keys():
    print(eachkeys)
#循环打印keys与values
for eachitem in brand.items():
    print(eachitem)
print(brand.get("","无此项"))#无此项
'''
"他"in brand 如果这个字典中有他就会返回True,没有则返回false,
brand.clear(),清空字典,copy()浅拷贝
'''

 

posted @ 2020-12-22 16:02  山君与见山  阅读(78)  评论(0编辑  收藏  举报