Python中map的用法

a={'Name':"Chen","age":20,"Major":"SoftWare Engineering"}
loc={
    "school":"SCU",
    "city":"ChengDu",
    "province":"SiChuan"

}
print(a)
a["year"]=2016#使用赋值来增加属性或者修改
print(a)
a.pop("Major")#弹出一个属性，即删除一个属性和值
print(a)
a["location"]=loc#增加一个同为map的属性
print(a)
del a["age"]#删除叫age的属性和值
print(a)

elem=0
for elem in a:#遍历所有的属性
    print(elem)

for elem in a.items():#遍历所有的记录（条目）
    print(elem)

for elem in a.keys():#遍历所有的属性
    print(elem)


b=a.copy()#拷贝到另一个map
print(b)

运行结果：

{'Name': 'Chen', 'age': 20, 'Major': 'SoftWare Engineering'}
{'Name': 'Chen', 'age': 20, 'Major': 'SoftWare Engineering', 'year': 2016}
{'Name': 'Chen', 'age': 20, 'year': 2016}
{'Name': 'Chen', 'age': 20, 'year': 2016, 'location': {'school': 'SCU', 'city': 'ChengDu', 'province': 'SiChuan'}}
{'Name': 'Chen', 'year': 2016, 'location': {'school': 'SCU', 'city': 'ChengDu', 'province': 'SiChuan'}}
Name
year
location
('Name', 'Chen')
('year', 2016)
('location', {'school': 'SCU', 'city': 'ChengDu', 'province': 'SiChuan'})
Name
year
location
{'Name': 'Chen', 'year': 2016, 'location': {'school': 'SCU', 'city': 'ChengDu', 'province': 'SiChuan'}}