PCPP2 Multiple Select — 50 Questions

Question 1

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

Accepted Answer

The start() method to begin execution.. Both modules provide mechanisms for joining, starting, and using locks for synchronization.

Answer

Direct access to the GIL.

Answer

Automatic shared memory.

Question 2

Which THREE of the following are benefits of using __slots__?

Accepted Answer

Faster attribute access. __slots__ reduces memory usage, prevents the creation of __dict__, and can potentially speed up attribute access.

Answer

Automatic support for multiple inheritance

Answer

Automatic serialization

Question 3

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

Accepted Answer

Threads present in the parent may not be safe in the child.. Forking a process inherits the parent's memory, which can lead to issues with locks and threads.

Answer

It cannot share data at all.

Answer

It crashes on all Unix systems.

Answer

It is always slower than spawn.

Question 4

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

Accepted Answer

socket.AF_INET. AF_INET and AF_INET6 are common address families, while SOCK_STREAM and SOCK_DGRAM are standard socket types.

Answer

socket.AF_TCP

Answer

socket.SOCK_LOCAL

Question 5

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

Accepted Answer

Using engine.execute('SELECT * FROM table'). SQLAlchemy allows executing raw SQL via text() with engine.execute() or session.execute().

Answer

Using session.query(RawSQL('SELECT * FROM table'))

Answer

Using session.commit('SELECT * FROM table')

Answer

Using table.run('SELECT * FROM table')

Question 6

Which TWO of the following scenarios are best suited for the subprocess module?

Accepted Answer

Running an external C++ executable.. Subprocess is intended for executing external binaries and interacting with their system streams.

Answer

Sharing memory between Python threads.

Answer

Managing internal thread pools.

Answer

Parallelizing Python functions.

Question 7

Which THREE of the following are common characteristics of the Observer pattern?

Accepted Answer

Automatic notification when the subject's state changes. One-to-many relationship, event notification, and loose coupling are key.

Answer

Observers are forced to be synchronous

Answer

The subject is tightly coupled to the concrete observers

Question 8

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

Accepted Answer

-m. -k allows filtering by substring and -m allows filtering by markers.

Answer

-v

Answer

-q

Answer

-s

Question 9

Which THREE of the following are valid ways to instantiate a process in the multiprocessing module?

Accepted Answer

By subclassing multiprocessing.Process.. Process can be instantiated directly, via target function, or by subclassing.

Answer

Using the multiprocessing.Queue method.

Answer

Using the threading.Thread class.

Question 10

Which THREE features are provided by 'pytest' but NOT by the standard 'unittest' framework?

Accepted Answer

Parametrization using markers.. pytest offers native parametrization, powerful fixture injection, and automatic test discovery without boilerplate classes.

Answer

Support for setup and teardown methods.

Answer

Basic assertion support.

Question 11

Which THREE of the following socket attributes or methods are relevant to managing socket timeouts?

Accepted Answer

socket.settimeout(). settimeout() sets the delay, gettimeout() retrieves it, and the socket might raise a timeout exception.

Answer

socket.listen()

Answer

socket.setblocking()

Question 12

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

Accepted Answer

socket.listen(). A TCP server uses bind() to assign the address and listen() to prepare for incoming connections.

Answer

socket.sendall()

Answer

socket.recvfrom()

Answer

socket.connect()

Question 13

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

Accepted Answer

It is inefficient for monitoring thousands of concurrent sockets.. select is limited by the maximum number of file descriptors (FD_SETSIZE) and is not as efficient as epoll/kqueue for massive numbers of connections.

Answer

It requires root privileges to execute.

Answer

It is significantly faster than epoll on all platforms.

Answer

It cannot be used with non-blocking sockets.

Question 14

Which TWO of the following are true regarding the socket.shutdown() method?

Accepted Answer

It can be used to disable only the receiving side of the socket.. shutdown() can disable reading, writing, or both, which is useful for protocol-level signaling.

Answer

It is identical to the close() method.

Answer

It causes an immediate memory deallocation of the socket object.

Answer

It automatically reopens the socket if called twice.

Question 15

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

Accepted Answer

Defining a function containing the 'yield' keyword. Generators can be created via generator expressions (using parentheses) or generator functions (using the yield keyword).

Answer

Calling the gen() function on a class

Answer

Using the @generator decorator

Answer

Using a list comprehension with brackets

Question 16

Which TWO of the following are common risks when implementing the Singleton pattern in Python?

Accepted Answer

Race conditions in multi-threaded environments during instantiation. Global state and threading issues are the most prominent risks when implementing the Singleton pattern.

Answer

Incompatibility with the abc module

Answer

Excessive subclassing of the Singleton class

Answer

Increased memory consumption for every instance

Question 17

Which THREE of the following are features of the 'threading' module in Python?

Accepted Answer

Semaphore objects. The threading module provides Locks, Semaphores, and Events for synchronization.

Answer

Shared memory between different processes

Answer

Automatic global interpreter lock removal

Question 18

Which THREE of the following are true about Python metaclasses?

Accepted Answer

Metaclasses are instances of 'type'. Metaclasses are types, they allow modifying class creation, and they are defined by inheriting from 'type'.

Answer

They are used to create instances directly

Answer

They are required for all classes in Python 3

Question 19

Which THREE of the following are standard ways to implement the 'Strategy' pattern in Python?

Accepted Answer

Injecting the strategy instance at runtime. Using functions, classes, or dependency injection are all valid strategies.

Answer

Hardcoding the strategy selection logic in the context

Answer

Using a global variable to change strategy behavior

Question 20

Which TWO of the following are valid ways to run tests?

Accepted Answer

python -m unittest. Both 'pytest' and 'python -m unittest' are the standard command-line ways to execute Python test suites.

Answer

unittest.execute()

Answer

python run_tests.py

Answer

import pytest; pytest.run()