notes/Python/python-基础-深浅拷贝.py at master · JavaDevTeam/notes · GitHub

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----------------------------

Python-浅拷贝 |

----------------------------

# 列表

arr1 = ['1','2','3']

arr2 = arr1.copy()

arr2[0] = '一'

print(arr1)

print(arr2)

# ['1', '2', '3']

# ['一', '2', '3']

arr1 = [[1,2],'2','3']

arr2 = arr1.copy()

arr2[0][0] = '一'

print(arr1)

print(arr2)

# [['一', 2], '2', '3']

# [['一', 2], '2', '3']

# 总结

* 潜拷贝,其实就是把列表中的所有元素的内存地址,都复制一份,放到了新的列表中

* 列表使用切片,也可以完成浅拷贝的效果

arr = [1,2,3]

arr.copy()

arr[:]

# 使用第三方模块完成浅拷贝

import copy

arr1 = [['1'],'2','3']

arr3 = copy.copy(arr1)

* 深拷贝

----------------------------

Python-深拷贝 |

----------------------------

# 深copy,是把值,进行复制,而不是地址值.

# 需要使用到模块

import copy

arr1 = [['1'],'2','3']

arr2 = copy.copy(arr1)

* 浅拷贝

arr3 = copy.deepcopy(arr1)

* 深拷贝

# demo

import copy

arr1 = [['1'],'2','3']

arr2 = copy.copy(arr1)

arr2[0][0] = '15' # 浅拷贝,直接修改会影响母体

arr3 = copy.deepcopy(arr1)

arr3[0][0] = '18' # 深拷贝,修改本体,不会影响母体

print(arr1) # [['15'], '2', '3']

print(arr2) # [['15'], '2', '3']

print(arr3) # [['18'], '2', '3']