PCPP1 Practice Test 1 — 25 Questions

Question 1

In the context of the Factory pattern, what does a concrete factory implement?

Accepted Answer

The creation interface for specific product variants.. A concrete factory implements the interface defined by the abstract factory to produce specific products.

Answer

The registration logic for all factories.

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The logic for the singleton pattern.

Answer

The product logic.

Question 2

You are writing a Python script that needs to send a GET request to a REST API and parse the JSON response. The API requires an API key passed as a query parameter. Which code snippet correctly performs this request using the requests library?

Accepted Answer

requests.get('https://api.example.com/data', params={'api_key': '12345'}). The params argument in requests.get() is the correct way to pass query parameters. It automatically URL-encodes the dictionary and appends it to the URL. Using headers or data would not place the API key in the query string as required. Manually constructing the URL is error-prone and less secure.

Answer

requests.get('https://api.example.com/data', data={'api_key': '12345'})

Answer

requests.get('https://api.example.com/data?api_key=12345')

Answer

requests.get('https://api.example.com/data', headers={'api_key': '12345'})

Question 3

Which standard Python library module is used for lower-level networking and creating server/client sockets?

Accepted Answer

socket. The socket module is Python's standard library interface to the BSD sockets API, providing low-level networking primitives for creating TCP/UDP clients and servers. It exposes functions like socket(), bind(), listen(), accept(), connect(), send(), and recv(), making it the correct answer for lower-level networking. Higher-level modules like http.server and third-party libraries like requests are built on top of it.

Answer

http.server

Answer

requests

Answer

networking

Question 4

In the csv module, how do you specify that the CSV file uses a semicolon (;) as a delimiter?

Accepted Answer

csv.reader(f, delimiter=';'). The delimiter parameter in the csv.reader or csv.writer function is used for this purpose.

Answer

csv.reader(f, char=';')

Answer

csv.reader(f, sep=';')

Answer

csv.reader(f, quotechar=';')

Question 5

You are creating a Tkinter GUI with a Canvas widget to draw a simple chart. You need to draw a filled blue rectangle from (50, 50) to (150, 100). Which Canvas method call achieves this?

Accepted Answer

canvas.create_rectangle(50, 50, 150, 100, fill='blue'). The Canvas widget offers dedicated factory methods for common shapes. create_rectangle takes two coordinate pairs that define the top-left and bottom-right corners and accepts a fill option for the interior colour. Using the correct method ensures the shape is actually a rectangle rather than a degenerate polygon, a thick line, or an ellipse.

Answer

canvas.create_polygon(50, 50, 150, 100, fill='blue')

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canvas.create_oval(50, 50, 150, 100, fill='blue')

Answer

canvas.create_line(50, 50, 150, 100, fill='blue', width=50)

Question 6

What is the primary difference between @classmethod and @staticmethod?

Accepted Answer

@classmethod receives the class as the first argument; @staticmethod does not.. @classmethod receives the class as the first argument, while @staticmethod receives no implicit class or instance argument.

Answer

@staticmethod can access instance variables.

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@classmethod is for private methods.

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@classmethod is slower.

Question 7

A developer is writing a Python module and wants to follow best practices for documenting functions. Which TWO of the following are recommended by PEP 257 for docstrings? (Choose two.)

Accepted Answer

The docstring should be enclosed in triple double quotes (""").. PEP 257 recommends using triple double quotes for docstrings and that they should describe the function's purpose and parameters. It also advises that a one-line docstring should end with a period, but does not require all docstrings to be single-line. No blank line should precede the docstring, and there is no rule about uppercase.

Answer

The docstring should be a single line that ends with a period.

Answer

The docstring should be separated from the function definition by a blank line.

Answer

The docstring should be written in all uppercase letters.

Question 8

What is the primary benefit of using 'logging' over 'print' statements for application diagnostics?

Accepted Answer

It allows setting severity levels and routing logs to different handlers.. The 'logging' module provides granular control over levels, destinations, and output formatting without changing the source code.

Answer

It is faster for small scripts.

Answer

It prevents the application from crashing on errors.

Answer

It automatically cleans up log files.

Question 9

You want to bind a function 'on_click' to a left mouse button click on a Button widget. Which event sequence string is correct?

Accepted Answer

. The event sequence '' corresponds to the primary (left) mouse button.

Answer

<Mouse-1>

Answer

<Left-Click>

Answer

<Click-1>

Question 10

Which method in the xml.dom.minidom module is used to retrieve the value of a specific attribute of an element?

Accepted Answer

element.getAttribute('attr_name'). The getAttribute() method is used to retrieve the value of an attribute by its name.

Answer

element.attr('attr_name')

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element.getAttributeNode('attr_name').value

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element.value('attr_name')

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element['attr_name']

Question 11

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. The requests.Session object is not thread-safe because it maintains shared state such as cookies, connection pools, and headers. Initializing a new Session inside each thread's run method ensures each thread has its own isolated session, avoiding race conditions and data corruption. This is the recommended practice for multithreaded scraping with requests.

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 12

You are refactoring code that performs sensitive operations. Which of the following is the most secure practice for handling secret keys?

Accepted Answer

Use environment variables to store sensitive configuration.. Hardcoding secrets is a major security vulnerability; using environment variables is the industry standard.

Answer

Encrypt the secrets and store them as constants in a module.

Answer

Store secrets in a private class attribute.

Answer

Hardcode them as strings inside a 'config.py' file and ignore it in Git.

Question 13

According to PEP 8, what is the maximum recommended length for a line of code?

Accepted Answer

79 characters.. PEP 8 suggests limiting lines to 79 characters to allow multiple files to be opened side-by-side.

Answer

80 characters.

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No limit.

Answer

120 characters.

Question 14

You are writing a Python utility that copies a directory tree to a network share using shutil. You must preserve file metadata and fail loudly if the destination already contains a conflicting file, rather than silently overwriting it. Which TWO shutil features satisfy these requirements? (Choose two.)

Accepted Answer

Leave the default behaviour of shutil.copytree() unchanged so that a pre-existing destination path raises FileExistsError.. Preserving metadata requires a copy function built on copystat, which copy2 provides, and copytree() exposes this through copy_function. Failing loudly on a pre-existing destination is the default copytree() behaviour, since dirs_exist_ok is False unless explicitly set. Together, copy_function=shutil.copy2 and the default dirs_exist_ok value satisfy both stated requirements.

Answer

Pass copy_function=shutil.copyfile to shutil.copytree() so existing files are never overwritten.

Answer

Pass dirs_exist_ok=True to shutil.copytree() so the copy proceeds when the destination directory already exists.

Answer

Pass copy_function=shutil.copy to shutil.copytree() so only permission bits are carried over.

Question 15

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

Answer

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

Question 16

You are designing a REST client that must call an endpoint protected by OAuth 2.0 using the client credentials grant. The authorization server expects the client identifier and client secret to be sent in the request body as `application/x-www-form-urlencoded`, along with `grant_type=client_credentials`. Which `requests` call correctly obtains the token?

Accepted Answer

requests.post(token_url, data={'grant_type': 'client_credentials', 'client_id': cid, 'client_secret': secret}). OAuth 2.0 token requests use POST with application/x-www-form-urlencoded bodies. The data parameter in requests performs that encoding automatically. Sending the grant type and client credentials in the body, rather than as Basic auth or JSON, satisfies the server's stated expectations and returns the access token needed for subsequent API calls.

Answer

requests.post(token_url, json={'grant_type': 'client_credentials', 'client_id': cid, 'client_secret': secret})

Answer

requests.post(token_url, auth=(cid, secret), data={'grant_type': 'client_credentials'})

Answer

requests.get(token_url, params={'grant_type': 'client_credentials', 'client_id': cid, 'client_secret': secret})

Question 17

In a Tkinter grid layout, you want a button to span across two columns. Which parameter should you use?

Accepted Answer

columnspan=2. The columnspan parameter in the grid() method manager allows a widget to occupy multiple columns.

Answer

span_cols=2

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merge=2

Answer

cols=2

Question 18

Which THREE practices improve documentation maintenance?

Accepted Answer

Updating documentation as part of the code review process.. Option A is correct because integrating documentation updates into the code review process makes doc changes a required, verifiable part of every pull request, so docs stay synchronized with code changes instead of drifting out of date. Option C is correct because following a consistent docstring format such as Google style enforces a uniform structure for parameters, returns, and raises sections, which makes documentation easier to read, review, and parse by tooling. Option E is correct because automatic documentation generation tools like Sphinx build docs directly from source docstrings, so regenerating after each change keeps published documentation current with minimal manual effort. Option B is not correct because writing docs only at the end of a project causes them to lag behind implementation and often results in incomplete or stale content. Option D is not correct because keeping documentation in a separate repository decouples it from the code, making it harder to update in the same commit or review cycle and increasing the risk of version mismatch.

Answer

Writing docs only at the end of the project.

Answer

Keeping documentation in a separate repository.

Question 19

What is the effect of setting __slots__ in a parent class on a child class that does not define its own __slots__?

Accepted Answer

The child class will have a __dict__ attribute, overriding the parent's optimization.. The child class will receive an instance __dict__ unless it also defines __slots__, effectively defeating the memory optimization of the parent.

Answer

The child class will raise an error at instantiation.

Answer

The child class will inherit the memory savings automatically.

Answer

The child class will be unable to add new attributes.

Question 20

What is the consequence of not calling super().__init__() in a class with multiple inheritance?

Accepted Answer

The initialization chain for parent classes is interrupted.. The MRO chain will break, and sibling classes may not be initialized properly, potentially causing missing attributes or logic errors.

Answer

The class will not be created.

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All attributes will be lost.

Answer

Python will raise a RuntimeError.