Demo1:

import copy 
dict1 = {'user':'runoob','num':[1,2,3]}

dict2 = dict1 
dict3 = dict1.copy()

dict1['num'].remove(1)
print(dict1)
print(dict2)
print(dict3)

Demo2:

import copy 
dict1 = {'user':'runoob','num':[1,2,3]}

dict2 = dict1 
dict3 = dict1.copy()

dict2['num'].remove(1)
print(dict1)
print(dict2)
print(dict3)

Demo3

import copy 
dict1 = {'user':'runoob','num':[1,2,3]}

dict2 = dict1 
dict3 = dict1.copy()

dict3['num'].remove(1)
print(dict1)
print(dict2)
print(dict3)

Demo4:

import copy 
dict1 = {'user':'runoob','num':[1,2,3]}

dict2 = dict1 
dict3 = copy.deepcopy(dict1)

dict1['num'].remove(1)
print(dict1)
print(dict2)
print(dict3)

Demo5:

import copy 
dict1 = {'user':'runoob','num':[1,2,3]}

dict2 = dict1 
dict3 = copy.deepcopy(dict1)

dict3['num'].remove(1)
print(dict1)
print(dict2)
print(dict3)

参考教程：https://www.runoob.com/python3/python3-att-dictionary-copy.html