数字类型总结

拷贝

• ==拷贝/浅拷贝/深拷贝都是针对可变类型数据而言的==

l1 = ['a','b','c',['d','e','f']]
l2 = l1

l1.append('g')

print(l1)  # ['a','b','c',['d','e','f'],'g']
print(l2)  # ['a','b','c',['d','e','f'],'g']

总结:如果l2是l1的拷贝对象,若l1内部的任意数据类型的元素变化,则l2内部的元素也会跟着改变,因为可变类型,值变id不变.

浅拷贝

import copy
l1 = ['a','b','c'['d','e','f']]
l2 = copy.copy(l1)

l1.append('g')

print(l1)  # ['a','b','c'['d','e','f'],'g']
print(l2)  # ['a','b','c'['d','e','f']

l1[3].append('g')
print(l1)  # ['a','b','c'['d','e','f','g'],'g']
print(l2)  # ['a','b','c'['d','e','f','g']]

总结:如果l2是l1的浅拷贝对象,若l1内的不可变元素发生了改变,l2不变;如果l1内的可变元素发生了改变,则l2也会跟着改变.

深拷贝

import copy
l1 = ['a','b','c'['d','e','f']]
l2 = copy.deepcopy(l1)

l1.append('g')

print(l1)  # ['a','b','c',['d','e','f'],'g']
print(l2)  # ['a','b','c'['d','e','f']]

l1[3].append('g')

print(l1)  # ['a','b','c'['d','e','f','g'],'g']
print(l2)  # ['a','b','c'['d','e','f']]

总结:如果l2是l1的深拷贝对象,若l1内的不可变类型元素发生改过,l2不会变;如果l1内的可变类型元素发生了变化,l2也不会改变,即l2永远不会因为l1的变化而变化.

python-数据类型总结 (面试常问)

原文：https://www.cnblogs.com/raynduan/p/10940426.html