计算在类中调用一个函数的次数

Question

I am trying to count the number of times the function obtainingparams within a class has been called and am using the decorator counted given below to do this. I know that this would work outside of a class, however, I get the error TypeError: counted() missing 1 required positional argument: 'fn' in the line @counted and don't know how to deal with this.

def counted(self, fn):
    def wrapper(*args, **kwargs):
        wrapper.called+= 1
        return fn(*args, **kwargs)
    wrapper.called= 0
    wrapper.__name__= fn.__name__
    return wrapper

@counted
def obtainingparams(self, df, tau_1, tau_2, residuals):
    print('Does something')

Thank You

Answer 1

Assuming counted is not defined inside a class then do the following:

def counted(fn):
    def wrapper(*args, **kwargs):
        wrapper.called+= 1
        return fn(*args, **kwargs)
    wrapper.called= 0
    wrapper.__name__= fn.__name__
    return wrapper

class MyClass(object):
    @counted
    def obtainingparams(self, df, tau_1, tau_2, residuals):
        print('Does something')

The only reason you would put self on a decorator would be if you were doing something like this:

class MyDecorator(object):
    def __init__(self):
        self.called = 0

    def counted(self, fn):
        def wrapper(*args, **kwargs):
            self.called += 1
            return fn(*args, **kwargs)
        wrapper.__name__= fn.__name__
        return wrapper

a_dec = MyDecorator()

class MyClass(object):
    @a_dec.counted
    def obtainingparams(self, df, tau_1, tau_2, residuals):
        print('Does something')