PCPP-32-101 1.12 Explain the Concept of Metaprogramming PCPP-32-1 Practice Questions (Page 3)

Questions 11–15

1. 11application · easy

   A developer is building a serialization library that needs to determine the type of an object to choose the correct serializer. The library receives objects of various types and must not import the types directly to avoid circular imports. Which attribute should the library use to inspect the object's type?

   • A`obj.__dict__`
   • B`obj.__name__`
   • C`obj.__class__`
   • D`obj.__bases__`
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2. 12foundation · easy

   Which method of a metaclass is typically overridden to intercept and modify the class creation process?

   • A__init__
   • B__call__
   • C__str__
   • D__new__
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4. 13foundation · easy

   In Python, what is the primary role of a metaclass?

   • AIt is a special method that is called when an object is garbage collected.
   • BIt is a base class that all user-defined classes must inherit from directly.
   • CIt is a decorator that modifies the behavior of a function at runtime.
   • DIt is a class whose instances are classes, controlling how classes are created and configured.
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5. 14expert · medium

   A team is building a framework that must ensure that all classes have a `registry_id` attribute. The attribute should be automatically assigned a unique integer when the class is defined. The team wants to avoid using a global counter that could be modified by other parts of the code. Which approach should be used?

   • AUse a metaclass that maintains a counter as a class variable on the metaclass and assigns it to each new class.
   • BUse `__init_subclass__` with a counter stored on the base class.
   • CUse `type()` to create classes manually and assign the counter.
   • DUse a global variable as a counter and increment it in a class decorator.
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6. 15application · medium

   A developer is building a plugin system where each plugin class must declare a `version` class variable. The system should automatically check that this variable exists and is a string when the class is defined. Which mechanism should be used?

   • AUse `__init_subclass__` to check the variable in each subclass.
   • BUse `type()` to create the class and manually check the variable.
   • CUse a class decorator that checks the class after definition.
   • DUse a metaclass that inspects the class namespace in `__new__` and raises an error if `version` is missing or not a string.
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