Python Institute Certified Professional in Python Programming 2 (PCPP2) (PCPP2) (PCPP2) — Questions 76–150

In the Observer pattern, what is the best way to prevent memory leaks when the Subject maintains a list of Observers?

Which THREE are valid cascade options in SQLAlchemy?

Which THREE of the following are valid ways to send or receive data?

Which THREE of the following represent ways to synchronize access to shared data in a multi-threaded application?

You are using the subprocess.run() function to execute an external command. Which argument ensures that the command's stdout is captured as a string rather than printed to the console?

Which magic method is used to define how an object is displayed for developers (for debugging)?

Which keyword is used to raise an exception in Python?

You are designing a class hierarchy where a subclass needs to ensure it calls the constructor of its parent in a multiple inheritance scenario. Which mechanism is the standard Pythonic approach to handle this dynamically?

Which TWO of the following pytest command-line options allow for filtering which tests are run?

Which TWO of the following are valid ways to create a generator in Python?

Which TWO of the following are common issues when using select.select()?

Which THREE attributes of 'unittest.mock.Mock' allow for verifying call interactions?

When using subprocess.Popen, why is it dangerous to use shell=True with user-supplied input?

You are utilizing the Mediator pattern to reduce coupling between components. Which of the following describes the role of the Mediator?

You are implementing the Command pattern. How can you best support the 'Undo' operation for a command that changes a document's state?

What is the purpose of the socket.recvfrom() method?

Which THREE operations are supported by the PyMongo 'bulk_write' method?

Which command-line argument shows the values of local variables in the event of a test failure?

When spawning processes on Windows, what is the default start method used by the multiprocessing module?

Two threads are modifying a shared global integer. You want to ensure that only one thread modifies the integer at a time. Which synchronization primitive is most appropriate?

You are using socket.socket(socket.AF_INET, socket.SOCK_DGRAM). You attempt to send 10,000 bytes via sendto(). Why might the operation raise an OSError?

You need to ensure that a method can be called on the class directly, without requiring an instance. Which decorator should be used?

Which THREE methods are part of the PEP 249 Python DB-API 2.0 interface?

Which TWO of the following methods are typically used on a TCP server socket?

Which THREE of the following are true about the 'subprocess' module's interaction with the operating system?

Which TWO of the following are potential issues when using the 'fork' start method in multiprocessing?

Which of the following describes the difference between Process.terminate() and Process.kill()?

Which THREE features are provided by SQLAlchemy's Unit of Work pattern?

Which THREE of the following features are common to both the threading and multiprocessing modules?

When handling TCP streams, why might recv(1024) return fewer than 1024 bytes even if the sender sent more?

Which THREE of the following are true regarding the use of 'unittest.mock.patch'?

When using select.select(inputs, outputs, exceptions), what does the 'outputs' list signify?

Which TWO of the following are true about the 'descriptor protocol' in Python?

In SQLAlchemy, how do you prevent an object from being saved to the database during a session.commit()?

You are implementing a Proxy pattern to provide lazy initialization for a resource-heavy object. Which technique is most effective for checking if the real object exists without triggering its constructor prematurely?

Which THREE are characteristics of BSON (Binary JSON) as used by MongoDB?

You are building an application using SSL/TLS. Which module must be used to wrap a standard socket to provide encrypted communication?

You need to compare two objects for equality based on a custom attribute. Which method should you override?

When using 'unittest', how do you ensure that a teardown method runs even if the test method raises an exception?

When using socket.setsockopt(), which option is required to immediately reuse a port that is currently in a TIME_WAIT state after a server restart?

When writing a context manager using the @contextlib.contextmanager decorator, what should the function do to pass a value to the 'as' clause?

Which THREE of the following are valid address families or socket types used with the Python socket module?

You are configuring a socket timeout. What happens if you call socket.settimeout(5.0) and the operation exceeds 5 seconds?

In pytest, how can you skip a test based on the operating system platform?

You are implementing the Visitor pattern to add operations to a set of stable class structures. Why is the 'Double Dispatch' mechanism essential?

Which TWO of the following are valid ways to implement the Proxy pattern in Python?

You are designing a State pattern. Which component is responsible for changing the state of the context object?

You are using 'slots' to save memory. What is a significant side effect of defining __slots__ in a class?

What is the purpose of the 'autospec' argument in 'patch'?

Which of the following is a valid way to run all tests in a directory using pytest?

Which TWO are common methods to handle BSON Date objects in PyMongo?

You want to store an object in a set. What must the object implement?

Which Python design principle is most strongly supported by the Adapter pattern?

Which TWO of the following are components of the Model-View-Controller (MVC) pattern frequently seen in Python web frameworks?

Which PyMongo method should be used to update a single document if you want to modify specific fields without replacing the entire document?

What is the significance of the SO_BROADCAST option in a UDP socket?

You are profiling your code and identify that a specific method is called millions of times. You decide to use a descriptor to optimize attribute access. What must the descriptor implement to intercept attribute assignment?

In a PyMongo application, what happens when you use 'insert_many' with 'ordered=False'?

You are using Pool.apply_async(). How do you retrieve the result of the function call?

When implementing the Strategy pattern, what is the best way to inject the strategy into the context object?

Why should you use a 'with' statement when using a Lock?

You are implementing a Prototype pattern. What is the difference between shallow copy and deep copy in the context of cloning objects?

You are managing subprocesses using subprocess.Popen. Which attribute of the Popen object should you check to verify the exit code after the process terminates?

Which TWO of the following are valid ways to execute a raw SQL query in SQLAlchemy?

In a Python TCP server, what is the primary purpose of the backlog parameter in the listen(backlog) method?

When connecting to a MongoDB instance using PyMongo, what is the role of the 'MongoClient' object?

When configuring a connection pool in SQLAlchemy, what does the 'pool_size' parameter define?

What command-line flag is used in pytest to stop the test suite execution after the first failure?

In SQLAlchemy, what is the difference between 'lazy='select'' and 'lazy='joined'' loading strategies?

When optimizing Python code, which tool should you use to identify hot spots in the execution path?

You are using the Composite pattern to represent a tree structure of UI elements. What is the most critical challenge when implementing a 'get_parent' method in this pattern?

Which 'unittest' assertion is best suited to verify that two floating-point numbers are equal within a certain tolerance?

How do you check how many times a mock object was called?

You are developing an application using SQLAlchemy and need to retrieve a single object by its primary key. Which method is preferred for this operation?

Which TWO of the following are Python object-oriented concepts?