一、数字和字符串 

对于数字和字符串而言，赋值、浅拷贝和深拷贝无意义，因为其永远指向同一个内存地址。



import copy

########## 数字、字符串 ###########
#n1 = 123
n1 = "i am a beautiful girl."
print(id(n1))
### 赋值 ###
n2 = n1
print(id(n2))
### 浅拷贝 ###
n2 = copy.copy(n1)
print(id(n2))

### 深拷贝 ###
n3 = copy.deepcopy(n1)
print(id(n3))



二、其他基本数据类型 

对于字典、元组、列表 而言，进行赋值、浅拷贝和深拷贝时，其内存地址的变化是不同的。 

1、赋值 

赋值，只是创建一个变量，该变量指向原来内存地址，如：



n1 = {"k1": "zhang", "k2": 123, "k3": ["mary", 456]}
n2 = n1



2、浅拷贝 

浅拷贝，在内存中只额外创建第一层数据



import copy

n1 = {"k1": " zhang ", "k2": 123, "k3": ["mary ", 456]}
n3 = copy.copy(n1)



3、深拷贝

深拷贝，在内存中将所有的数据重新创建一份（排除最后一层，即：python内部对字符串和数字的优化）



import copy

n1 = {"k1": " zhang ", "k2": 123, "k3": ["mary ", 456]}  
n4 = copy.deepcopy(n1)



应用： 

浅拷贝



import copy

dic = {
    "cpu":[80,],
    "mem":[80,],
    "disk":[80,],
}
print("before dic",dic)
new_dic = copy.copy(dic)
new_dic["cpu"][0] = 50
print("new_dic dic",new_dic)
print("after dic",dic)

运行结果：



before dic {'cpu': [80], 'mem': [80], 'disk': [80]}
new_dic dic {***'cpu': [50]***, 'mem': [80], 'disk': [80]}
after dic {'***cpu': [50]***, 'mem': [80], 'disk': [80]}

深拷贝



import copy

dic = {
    "cpu":[80,],
    "mem":[80,],
    "disk":[80,],
}
print("before dic",dic)
new_dic = copy.deepcopy(dic)
new_dic["cpu"][0] = 50
print("new_dic dic",new_dic)
print("after dic",dic)

输出结果： 

before dic {‘cpu’: [80], ‘mem’: [80], ‘disk’: [80]} 

new_dic dic {‘cpu’: [50], ‘mem’: [80], ‘disk’: [80]} 

after dic {‘cpu’: [80], ‘mem’: [80], ‘disk’: [80]}