copy.deepcopy()的使用方法
时间: 2023-12-11 12:48:37 浏览: 25
copy.deepcopy()可以完整复制一个对象及其所有属性,包括嵌套对象。具体使用方法如下:
```python
import copy
# 原始对象 obj
obj = {
"a": [1, 2, 3],
"b": {
"c": 4,
"d": 5
}
}
# 完整复制对象 copy_obj
copy_obj = copy.deepcopy(obj)
# 修改原始对象 obj 中的内容
obj["a"].append(4)
obj["b"]["c"] = 6
# 打印结果对比
print("obj: ", obj)
print("copy_obj: ", copy_obj)
```
输出结果为:
```python
obj: {'a': [1, 2, 3, 4], 'b': {'c': 6, 'd': 5}}
copy_obj: {'a': [1, 2, 3], 'b': {'c': 4, 'd': 5}}
```
可以看到,使用完整复制方法copy.deepcopy()复制对象之后,修改原始对象obj并不会影响复制出来的对象copy_obj。
相关问题
copy.deepcopy
The `copy.deepcopy()` method is a function in Python's `copy` module that creates a deep copy of an object. A deep copy creates a new object and recursively copies all nested objects as well. This means that any changes made to the original object will not affect the copy, and vice versa.
Here's an example of how to use `copy.deepcopy()`:
```
import copy
original_list = [1, 2, [3, 4]]
deep_copy_list = copy.deepcopy(original_list)
# Modify the original list
original_list[2][0] = 5
print(original_list) # Output: [1, 2, [5, 4]]
print(deep_copy_list) # Output: [1, 2, [3, 4]]
```
In this example, `original_list` contains a nested list. When we create a deep copy of `original_list` and modify the nested list in `original_list`, the nested list in `deep_copy_list` remains unchanged. This is because `copy.deepcopy()` created a new nested list in `deep_copy_list` instead of referencing the original nested list.
copy.deepcopy()用法
copy.deepcopy()是一个Python中的模块,它可以使我们深度复制一个对象。这个模块非常有用,因为它可以避免对象的浅复制问题。浅复制只是复制一个对象的引用,而不是它的值。使用深度复制可以创建一个完全独立的副本,它的所有属性都是完全独立的。例如:
import copy
original_list = [1, 2, [3, 4]]
new_list = copy.deepcopy(original_list)
new_list[2][0] = 5
print(original_list) # [1, 2, [3, 4]]
print(new_list) # [1, 2, [5, 4]]
注意,使用深度复制非常耗费资源和时间,因为它会完全复制一个对象及其所有子对象。所以,在使用copy.deepcopy()之前,请确保对象是可以全面复制的,并且确实需要进行深度复制。