PCPP1 Networking And Restful Apis — 10 Questions

Question 1

When working with raw sockets, what does the 'socket.SOCK_STREAM' constant represent?

Accepted Answer

TCP connection-oriented sockets. SOCK_STREAM is used for TCP connections, which are connection-oriented and reliable.

Answer

UDP datagram sockets

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Raw network sockets

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Unix domain sockets only

Question 2

You are using the socket module to create a TCP client. After creating the socket object, which method call is required to establish a connection to a remote server listening on 192.168.1.50 at port 8080?

Accepted Answer

sock.connect(('192.168.1.50', 8080)). The connect method is used on a client-side socket to initiate a TCP three-way handshake with a remote server.

Answer

sock.bind(('192.168.1.50', 8080))

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sock.accept()

Answer

sock.listen(1)

Question 3

You are consuming a REST API that returns data in JSON format. After calling response.json(), you notice the data contains nested dictionaries. What is the most Pythonic way to handle a missing key in the response dictionary safely?

Accepted Answer

Use response.json().get('key', default_value). The dict.get() method provides a way to access a key with a default value if the key does not exist, preventing a KeyError.

Answer

Wrap the access in a try-except KeyError block

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Check 'if 'key' in response.json():' before access

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Use response.json()['key'] and assume the API schema is always correct

Question 4

When using the 'socket' module, what is the effect of calling 'socket.settimeout(5.0)' on a socket object?

Accepted Answer

It causes the operation to raise a socket.timeout after 5 seconds. The settimeout() method sets a timeout in seconds for subsequent socket operations. If the operation does not complete within the time, a socket.timeout exception is raised.

Answer

It sets the send buffer size to 5.0 bytes

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It blocks the thread for exactly 5 seconds

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It forces the socket to close after 5 seconds of inactivity

Question 5

In the 'requests' library, which HTTP method is typically used to update an existing resource on a server?

Accepted Answer

PUT. The PUT method is standard for replacing or updating an existing resource at a specific URI.

Answer

POST

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GET

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DELETE

Question 6

You are building a REST client that needs to handle 429 Too Many Requests status codes. Which strategy is most effective when implementing an automatic retry mechanism?

Accepted Answer

Implement an exponential backoff strategy with jitter. Implementing exponential backoff ensures that you do not overwhelm the server while waiting for the rate limit to reset.

Answer

Switch to a different base URL immediately

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Ignore 429 errors and continue execution

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Retry immediately in a loop until successful

Question 7

When using the 'requests' library to perform a GET request, which parameter should be passed to the 'params' argument to include query string parameters in the URL?

Accepted Answer

A dictionary. The 'params' argument expects a dictionary of key-value pairs which the library automatically encodes and appends to the URL.

Answer

A tuple of values

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A single formatted string

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A list of strings

Question 8

You are developing a multithreaded HTTP scraper. When using the 'requests' library inside 'threading.Thread' objects, what is the recommended practice for handling session persistence?

Accepted Answer

Initialize a new Session object inside each thread's run method. Requests.Session objects are not thread-safe in a way that prevents race conditions on connection pools. Each thread should ideally have its own session or a thread-safe connection pool mechanism.

Answer

Wrap the session object in a threading.Lock

Answer

Share a single global Session object across all threads

Answer

Disable connection pooling using 'pool_connections=0'

Question 9

When using 'requests.get()', how can you include a custom HTTP header in your request?

Accepted Answer

Use the 'headers' dictionary argument. The 'headers' parameter accepts a dictionary of HTTP headers.

Answer

Use the 'data' argument

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Pass it as part of the URL string

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Use the 'params' dictionary

Question 10

What is the purpose of the 'socket.shutdown()' method in Python?

Accepted Answer

It stops further communication on the socket. shutdown() allows you to stop sending or receiving data on a socket while keeping the file descriptor open.

Answer

It forces the socket to release its memory

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It resets the socket connection immediately

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It closes the file descriptor completely