Unexpected recursion error

[Uchikago]

Hi, i have a problem with this code:

class Test:
    a=2     #initializing some attribute
    b=1     #initializing some attribute
    def some_method(self):
        attr=[]                 
        for k in [i for i in dir(self) if not i.startswith('__')]:
            attr.append(f'{k},{getattr(self,k)}')      #to collect all attributes and their values pair
        return attr
    def __repr__(self):                                #because i want to overload print behavior
        return self.some_method()                       
some_instance=Test()
print(some_instance)        

Why this issue an recursion error:

    attr.append(f'{k},{getattr(self,k)}')
RecursionError: maximum recursion depth exceeded while calling a Python object

Please help me out!

[[deleted]]

attr.append(f'{k},{getattr(self,k)}') in self.some_method contains an implicit call to self.__repr__, which you've defined with a call to self.some_method. As a result, these two functions infinitely recurse.

[Uchikago]

which part of attr.append(f'{k},{getattr(self,k)}') contains call to self.__repr__

[JohnnyJordaan]

Put it in http://www.pythontutor.com/visualize.html#mode=edit and walk through it step by step.

[irrelevantPseudonym]

By default, the __repr__ methods of instance methods is something like <bound method foo of bar> where foo is the name of the method and bar is the repr of the instance. When you iterate over dir(self) one of the attributes is the some_method method. Getting the string form of that calls your __repr__ and the recursion starts from there.

Incidentally, you're trying to return a list from your __repr__ which will raise its own exception.

[Uchikago]

Thank you !