如何对一个函数使用多个装饰器并将它们链接在一起？

Question

如何在 Python 中创建两个装饰器来执行以下操作？

@check_zero_error
@check_numerator
def division(a, b):
    return a/b

如果分子小于分母，

'check_numerator' 将反转数字。

'check_zero_error' 将检查除零错误。

预期输出为：

division(1, 2)   # Output : 2.0

division(0, 2)   # Output : "Denominator can't be zero"
 
division(4, 1)   # Output : 4.0

division(5, 0)   # Output : "Denominator can't be zero"

我的代码如下，但没有得到预期的结果：

def check_zero_error(division_func):
    def inner(a, b):
        if b == 0:
            return "Denominator can't be zero"
        else:
            division_func(a, b)
    return inner

def check_numerator(division_func):
    def inner(a, b):
        if a < b:
            a, b = b, a
        division_func(a, b)
    return inner


@check_zero_error
@check_numerator
def division(a, b):
    return a/b
       

print(division(1, 2))  # Expected output : 2.0
print(division(0, 2))  # Expected output : "Denominator can't be zero"
print(division(4, 1))  # Expected output : 4.0

Answer 1

你的装饰器方法应该return除法的结果

def check_zero_error(division_func):
    def inner(a, b):
        if b == 0:
            return "Denominator can't be zero"
        else:
            return division_func(a, b)
    return inner

def check_numerator(division_func):
    def inner(a, b):
        if a < b:
            a, b = b, a
        return division_func(a, b)
    return inner

更改装饰器的顺序，首先 swap (check_numerator) 然后如果需要，然后用 check_zero_error
检查分母
```
@check_numerator
@check_zero_error
def division(a, b):
    return a / b
```

给予预期

print(division(1, 2))  # actual output : 2.0
print(division(0, 2))  # actual output : "Denominator can't be zero"
print(division(4, 1))  # actual output : 4.0
print(division(5, 0))  # actual output :  "Denominator can't be zero"

如何对一个函数使用多个装饰器并将它们链接在一起？

How to use multiple decorator to a function and chain them together?

python

function

python-decorators