CODEWITHSUNDEEP
pythoninstancecallable
nerdoc
nerdoc

Reputation: 1083

Dynamically call staticmethod in Python

I have a python object that has various attrs, one of them is check=None.

class MenuItem:
    check: bool = True

During the __init__() process, it parses it's own attrs and looks if they are callable. If so, it calls the function, and replaces it's instance variable with the result of the function:

    def __init__(self):
        self.request = ...
        if callable(self.check):
            self.check = self.check(self.request)

The purpose is to have subclasses that may replace class attrs by lambda functions:

class MainMenuItem(MenuItem):
    check = lambda request: request.user.is_authenticated

So far, so good. But as the calling of instance methods implicitly adds self as first parameter, I would have to write every lambda (or external function) as lambda self, request: ... - external functions must be def check_superuser(self, request): ... - which IMHO looks bad.

Is there a way in Python to call a function from a method "as staticmethod"? Like

if callable(self.check):
    self.check = staticmethod(self.check)(self.request)

(this obviously doesn't work)

Any hint's welcome. Do I completely think wrong?

Upvotes: 1

Views: 95

Answers (1)

Antony Hatchkins
Antony Hatchkins

Reputation: 33974

Is this what you are looking for?

class A:
    check: bool = True
    def __init__(self):
        self.request = 'request'
        if callable(self.check):
            self.check = self.__class__.check(self.request)

class B(A):
    check = lambda request: len(request)

b = B()
print(b.check)

outputs 7

Upvotes: 2

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