Passing parameters to decorator at runtime

Question

If I create a python decorator function like this

def retry_until_true(tries, delay=60):
    \"\"\"
    Decorator to rety a function or method until it retur         


        

Answer 1

You can use a class as a decorator, with instance variables for tries and delay:

class RetryUntilTrue(object):
    def __init__(self, f=None, tries=10, delay=30):
        self.f = f
        self.tries = tries
        self.delay = delay

    def __call__(self, *args, **kwargs):
        if self.f is None:
            self.f = args[0]
        else:
            tries = self.tries
            while tries:
                if self.f(*args, **kwargs):
                    return True

                tries -= 1
                time.sleep(self.delay)

Usage:

@RetryUntilTrue
def foo(x):
    pass

foo.tries = 20
foo.delay = 1

@RetryUntilTrue(tries=100, delay=9999)
def bar(x):
    pass

bar.tries -= 1
bar.delay = foo.delay

Answer 2

Sure you can, just nest your function definition in another function, for example:

def explicit_setup_func(tries, delay=60):
    @retry_until_true(tries, delay)
    def check_something_function(x, y):
        # Code

However, the class decorator solution is more practical.