A confused for python decorator

Question

deco1:

def deco(func):
    def wrapper(*args, **kwargs):
        f = func(*args, **kwargs)
        print("deco success")
        return f

return wrapper

deco2:

def deal_exc(func):
    def wrapper(*arg, **kwargs):
        try:
             return func(*arg, **kwargs)
        except Exception as e:
             print(str(e))

    return wrapper

use decos:

@deal_exc
@deco
def a_function():
    print(0 / 100)
    raise Exception("666")

how to skip print("deco success") when i raise an exception and let deal_exc decorator deal with the exception?

Answer 1

When you put a decorator above a decorator, the upper decorator actually wraps(read calls) the lower decorator & similarly, the lower decorator wraps(read calls) the actual function.

So, you cannot skip the handling unless you remove the decorator.

In case you want the inner decorator(deco) to NOT handle some specific scenario, you'll have to apply checks for it. eg:

In the above case, since there is no try-catch handling in the inner decorator, the exception thrown by the function will automatically be handled by the outermost decorator(deal_exc).