PCPP-32-101 1.11 (De)serialize Python Objects PCPP-32-1 Practice Questions (Page 3)

Questions 11–15

1. 11foundation · easy

   Which code snippet correctly serializes a Python list to a bytes object using the pickle module?

   • Adata = pickle.dumps([1, 2, 3])
   • Bdata = pickle.dump([1, 2, 3])
   • Cdata = pickle.loads([1, 2, 3])
   • Ddata = pickle.serialize([1, 2, 3])
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2. 12expert · hard

   A developer is designing a system that needs to persist a Python object that contains a reference to a file handle. The developer tries to use pickle.dump() but receives a TypeError. What is the most likely reason?

   • AFile handles are not picklable because they represent OS-level resources that cannot be serialized.
   • BThe developer used the wrong protocol version.
   • CThe developer used pickle.dumps() instead of pickle.dump().
   • DThe developer opened the file in text mode instead of binary mode.
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4. 13application · medium

   A data science team is building a pipeline that trains a machine learning model and then needs to save the trained model object to disk so it can be loaded later for predictions. The model object contains custom classes and complex internal state. The team does not need the model to be readable by any other language. Which serialization approach is most appropriate?

   • AUse json.dump() to save the model as a JSON file.
   • BUse pickle.dump() to save the model object to a binary file.
   • CUse csv.writer() to save the model parameters to a CSV file.
   • DUse repr() to save a string representation of the model.
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5. 14foundation · easy

   Which statement about the shelve module is true?

   • AIt provides a persistent dictionary-like object whose values can be any picklable Python object.
   • BIt can only store string keys and string values.
   • CIt automatically encrypts the data to protect sensitive information.
   • DIt stores data in a plain text file that can be read with a standard text editor.
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6. 15expert · hard

   A company runs a Python application that processes financial transactions. The application maintains a dictionary of active sessions, where each session is a custom class instance containing sensitive data. The sessions must be persisted to disk so that the application can be restarted without losing active sessions. The security team requires that the data be stored in a format that is not human-readable and that the file be locked to prevent concurrent access from multiple processes. The application also needs to update individual session records frequently. Which approach best meets all requirements?

   • AUse shelve.open() with the 'c' flag to create the database and access individual keys.
   • BUse pickle.dump() to serialize the entire dictionary to a file after each update.
   • CUse json.dump() to write the dictionary to a JSON file with indentation.
   • DUse csv.writer() to write each session as a row in a CSV file.
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