Python3 list 浅拷贝，深拷贝

list1 = [1, 2, 3, 4]
list2 = list1
print('list1 ', list1)  # list1  [1, 2, 3, 4]
print('list2 ', list2)  # list2  [1, 2, 3, 4]
del list2[0]
print('list1 ', list1)  # list1  [2, 3, 4]
print('list2 ', list2)  # list2  [2, 3, 4]

import copy
list3 = [5, 6, 7, 8]
list4 = copy.deepcopy(list3)
print('list3 ', list3)  # list3  [5, 6, 7, 8]
print('list4 ', list4)  # list4  [5, 6, 7, 8]
del list4[0]
print('list3 ', list3)  # list3  [5, 6, 7, 8]
print('list4 ', list4)  # list4  [6, 7, 8]