can any recursive looping happen from overwriting __dir__ in python -

suppose, have custom class not inherit class (which typically hard inherit from), builds wrapper along few other functions modify behavior of second class.

class testclass:    def __init__(self, *args, **kwargs):        self.data = origclass(*args, **kwargs)     def __getitem__(self, key):        ...        x = self.data.__getitem__(key)        ...     def __setitem__(self, key, value):        ...        self.data.__setitem__(key, value)        ...     @staticmethod    def _try_attr(var, item):        if hasattr(var, item):            return var.__getattribute__(item)        else:            return none      def __getattr__(self, item):        return testclass._try_attr(self._data, item)      def __repr__(self):        ...     def __str__(self):        ... 

as such, testclass working fine new modifications, , falling on origclass methods using __getattr__ methods not re-implemented. however, in interactive mode (e.g. pycharm's python console) or otherwise, when try see __dir__(), __dir__() in testclass doesn't display / show attributes in origclass accessible in testclass.

i can try create new __dir__ function within testclass merge current testclass's __dir__ __dir__ in origclass create __dir__ (i'm using python 3.x). there seems posts on over (although not sure of them valid python 3.x).

1. however, worried common functions in origclass , testclass, i.e. if there functions __setitem__, __getitem__ in both origclass , testclass, ones new __dir__ refer to?

2. are there other functions (e.g. __ functions such __getitem__, __setattr__ etc.) refer __dir__? or, in other words, chance of falling recursive loop if overwrite __dir__?

1. __dir__ returns list of unique strings; it'll include strings '__setitem__' , '__getitem__' without reference specific implementation.

   in other words, doesn't matter if refer testclass or origclass implementation. accessing attribute name on testclass find testclass implementation.

2. __dir__ purely informative , used dir() command. other tools (such python help() system) may rely on dir().

   you'll not recursive loop, method entirely optional, there no base implementation dir() otherwise collects information object other means.

you can use dir() on self.data attribute, , append resulting list create testclass version:

def __dir__(self):     base = dir(self.data)     base.extend(('_try_attr', 'data'))     return base 

the resulting list of strings sorted again dir().