Child classes do not call the __init__ method of the base class #2378

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1. DimitriPapadopoulos

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   bugPotential issues with the zarr-python libraryPotential issues with the zarr-python library

   on Oct 15, 2024
2. jhamman commented on Oct 15, 2024

   

   jhamman

   on Oct 15, 2024

   Last edited by jhamman

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   storage.logging.LoggingStore.init does not call abc.store.Store.init

   This is the expected behavior. The LoggingStore wraps another Store object and the assumption is that this store called super().__init__(). I don't think it would make sense to call it again.
3. DimitriPapadopoulos commented on Oct 16, 2024

   

   DimitriPapadopoulos

   on Oct 16, 2024

   Last edited by DimitriPapadopoulos

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   While the child class does not have to call super.__init__(), it is usually expected to.

   In this specific case, LoggingStore inherits Store. If possible, LoggingStore.__init__ should call Store.__init__. That does seem possible and preferable here, as the base class initialises some private variables in Store.__init__:

           self._is_open = False
           self._mode = AccessMode.from_literal(mode)

   which the child class does not initialise in LoggingStore.__init__:

           self._store = store
           self.counter = defaultdict(int)
           self.log_level = log_level
           self.log_handler = log_handler
   
           self._configure_logger(log_level, log_handler)

   Shouldn't the variables of the base class be initialised when creating a child class? I may be missing something, but then it could mean that the code is overly complex, breaking usual assumptions without any visible explanation.

   Said otherwise, why have a non-empty __init__ in an abstract base class, if it is not called by child classes?
4. d-v-b

   closed this as completedin #4102on Jul 2, 2026