python多层装饰器执行顺序
时间: 2023-12-11 07:33:51 浏览: 39
Python中多层装饰器的执行顺序是从下往上执行,即先执行最底层的装饰器,然后依次向上执行。在你提供的例子中,执行顺序如下:
1.首先,@deco2装饰器被执行,因为它在@deco1之下,所以它是最底层的装饰器。执行结果为:
```python
5
```
2.然后,@deco1装饰器被执行,因为它在foo函数之上。执行结果为:
```python
1
```
3.接着,wrapper1函数被创建并返回,因为它是@deco1装饰器内部定义的。执行结果为:
```python
2
foo
3
4
```
4.最后,wrapper2函数被创建并返回,因为它是@deco2装饰器内部定义的。执行结果为:
```python
6
2
foo
3
4
7
8
```
因此,最终的输出结果为:
```python
5
1
6
2
foo
3
4
7
8
```
相关问题
python装饰器执行顺序
装饰器的执行顺序是按照装饰器被调用的顺序来决定的。在多个装饰器的情况下,装饰器是从上到下依次被调用的。先执行最上面的装饰器,然后再执行下面的装饰器。这意味着被装饰的函数首先会经过最上面的装饰器的处理,然后再经过下面的装饰器的处理。因此,在多个装饰器的情况下,装饰器的执行顺序是自上而下的。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
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python多个装饰器执行顺序
在Python中,如果一个函数使用了多个装饰器,那么它们的执行顺序是从下往上的。也就是说,最下面的装饰器最先执行,最上面的装饰器最后执行,函数执行完后,装饰器的执行顺序则与装饰器定义的顺序相反。
例如,下面是一个使用三个装饰器的示例:
``` python
def decorator1(func):
def wrapper(*args, **kwargs):
print("Decorator 1 before function execution")
func(*args, **kwargs)
print("Decorator 1 after function execution")
return wrapper
def decorator2(func):
def wrapper(*args, **kwargs):
print("Decorator 2 before function execution")
func(*args, **kwargs)
print("Decorator 2 after function execution")
return wrapper
def decorator3(func):
def wrapper(*args, **kwargs):
print("Decorator 3 before function execution")
func(*args, **kwargs)
print("Decorator 3 after function execution")
return wrapper
@decorator1
@decorator2
@decorator3
def my_function():
print("Function execution")
my_function()
```
输出结果为:
```
Decorator 3 before function execution
Decorator 2 before function execution
Decorator 1 before function execution
Function execution
Decorator 1 after function execution
Decorator 2 after function execution
Decorator 3 after function execution
```
可以看到,装饰器3最先执行,然后是装饰器2,最后是装饰器1。而函数执行完后,装饰器的执行顺序则与装饰器定义的顺序相反,即装饰器1最先执行,然后是装饰器2,最后是装饰器3。
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