python copy函数用法_copy.copy()函数用法

b = copy.copy(a)

copy.copy这个函数结果会因为是可变或者不可变导致结果不同

只能拷贝一层。根据类型有关。如果是列表(可变类型)，深拷贝。如果是元组(不可变)浅拷贝

如果里面还有嵌套的对象，浅拷贝

import copy

a = [1,2,3,4]

#相当于深拷贝

b = copy.copy(a)

print(id(a))

print(id(b))

a.append(5)

print(a)

print(b)

运行结果：

18904264

18489224

[1, 2, 3, 4, 5]

[1, 2, 3, 4]

import copy

a = (1,2,3,4)

#相当于浅拷贝

b = copy.copy(a)

print(id(a))

print(id(b))

运行结果：

18713160

18713160

import copy

a = [11,22,33]

b = [44,55,66]

c = [a,b]

d = copy.copy(c)

print(id(c))

print(id(d))

print(c)

print(d)

a.append(120)

#c[0].append(120)

print(c)

print(d)

运行结果：

18772104

7561416

[[11, 22, 33], [44, 55, 66]]

[[11, 22, 33], [44, 55, 66]]

[[11, 22, 33, 120], [44, 55, 66]]

[[11, 22, 33, 120], [44, 55, 66]]

import copy

a = [11,22,33]

b = [44,55,66]

c = (a,b)

d = copy.copy(c)

print(id(c))

print(id(d))

print(c)

print(d)

a.append(120)

#c[0].append(120)

print(c)

print(d)

运行结果：

10951368

10951368

([11, 22, 33], [44, 55, 66])

([11, 22, 33], [44, 55, 66])

([11, 22, 33, 120], [44, 55, 66])

([11, 22, 33, 120], [44, 55, 66])