PCAP Modules and Packages Practice Test 4 — 15 Questions

Question 1

Drag and drop the steps to perform unit testing with the unittest framework in Python into the correct order.

Accepted Answer

Import unittest, then create a TestCase subclass, then define test methods (starting with 'test_'), then call unittest.main(). Unit testing with unittest requires importing, creating a TestCase subclass, writing test methods, and calling unittest.main().

Answer

Create a TestCase subclass, then import unittest, then define test methods, then call unittest.main()

Answer

Import unittest, then define test methods, then create a TestCase subclass, then call unittest.main()

Answer

Import unittest, then create a TestCase subclass, then call unittest.main(), then define test methods

Question 2

Match each Python built-in function to its description.

Accepted Answer

len(): Returns the length (number of items) of an iterable.. The correct matches are: len() returns length, map() applies a function, filter() filters by truth, zip() combines iterables. Common confusions involve swapping the definitions of map and len, or filter and zip.

Answer

len(): Applies a function to every item of an iterable and returns a map object.

Answer

map(): Returns the length (number of items) of an iterable.

Question 3

Match each code snippet to its output.

Accepted Answer

2 + 3 * 4: 14. Understand operator precedence: exponentiation > multiplication/division > addition/subtraction. Parentheses override precedence. Integer division (//) returns floor division quotient, while modulo (%) returns remainder.

Answer

2 ** 3: 6

Answer

10 // 3: 1

Question 4

During development, a programmer modifies a module that is already imported in the current Python session. To see the changes without restarting the interpreter, which function from the importlib module should be called?

Accepted Answer

importlib.reload(). `importlib.reload()` is the official Python function to re-import a previously imported module, applying any changes made to its source code without restarting the interpreter. It is part of the `importlib` module and is the recommended way to reload modules in Python 3.

Answer

reload()

Answer

reload_module()

Answer

importlib.import_module()

Question 5

Given package structure: pack/__init__.py, pack/subpack/__init__.py, pack/subpack/mod.py. Inside pack/__init__.py, which import statement correctly imports mod.py using a relative import?

Accepted Answer

from .subpack import mod. `from .subpack import mod` uses a leading dot to indicate a relative import from the current package (`pack`), then navigates into `subpack` and imports `mod`. This is the proper syntax for importing a module from a subpackage within the same parent package.

Answer

from . import subpack.mod

Answer

from subpack import mod

Answer

from ..subpack import mod

Question 6

A Python script fails with 'ModuleNotFoundError: No module named 'myapp.config''. The environment variable PYTHONPATH is not set. Which of the following is the most likely cause?

Accepted Answer

The module is located in a directory not included in sys.path. When PYTHONPATH is not set, Python relies solely on sys.path to locate modules. sys.path includes the script's directory, standard library paths, and site-packages. If 'myapp.config' is not in any of these directories, Python raises ModuleNotFoundError. Option A correctly identifies that the module is in a directory not included in sys.path.

Answer

The module's __init__.py is missing

Answer

The module is installed in a different Python version's site-packages

Answer

The module has a syntax error

Question 7

Which of the following statements about the __init__.py file in a package is true?

Accepted Answer

It is required for a directory to be considered a regular package. In Python, a directory containing an `__init__.py` file is recognized as a regular package. This file can be empty or contain initialization code, and its presence is required for the directory to be imported as a package (as opposed to a namespace package). Without it, Python will not treat the directory as a regular package.

Answer

It is required for a namespace package

Answer

It cannot contain executable code

Answer

It is automatically generated by Python

Question 8

A team is developing a large application and wants to organize code into packages. Which of the following is a best practice for package design?

Accepted Answer

Use absolute imports with the package name to prevent breakage when the package is moved. Using absolute imports with the full package name (e.g., `from package.module import something`) ensures that the import path is explicit and independent of the module's location within the package. This prevents breakage when the package is moved or installed in a different location, as the import references the top-level package name rather than a relative path that may change. Absolute imports are the recommended style in PEP 8 for clarity and maintainability in larger applications.

Answer

Use relative imports inside the package to avoid hardcoding the package name

Answer

Keep all modules in a single package for simplicity

Answer

Avoid using __init__.py to keep packages lightweight

Question 9

A developer runs 'pip install mypackage' but gets a 'PermissionError'. Which command should be used to install the package for the current user only?

Accepted Answer

pip install --user mypackage. The `--user` flag instructs pip to install the package into the user's site-packages directory (e.g., `~/.local/lib/pythonX.Y/site-packages` on Unix), which does not require elevated permissions. This avoids the `PermissionError` that occurs when pip tries to write to the system-wide site-packages directory (e.g., `/usr/lib/python3/dist-packages`) without administrator privileges.

Answer

sudo pip install mypackage

Answer

pip install --ignore-installed mypackage

Answer

pip install --target mypackage

Question 10

When importing a module, Python searches for it in a specific order. Which of the following lists the correct order of directories searched?

Accepted Answer

[current directory] then PYTHONPATH then site-packages. When Python imports a module, it first searches the directory containing the input script (or current working directory), then iterates through the directories listed in the PYTHONPATH environment variable, and finally checks installation-dependent default paths such as site-packages. This order is reflected in sys.path, which is built from the script directory, PYTHONPATH entries, and default site-packages. Option B accurately lists this sequence: current directory, then PYTHONPATH, then site-packages.

Answer

PYTHONPATH then sys.path

Answer

sys.path + [current directory]

Answer

[current directory] + sys.path

Question 11

Which of the following is a valid way to import a module named 'math' and assign it an alias 'm'?

Accepted Answer

import math as m. Python's `import` statement allows you to import a module and assign it an alias using the `as` keyword, as in `import math as m`. This creates a reference to the `math` module under the name `m`, so you can call functions like `m.sqrt(16)` without polluting the namespace with the original module name.

Answer

alias math as m

Answer

from math import * as m

Answer

import m from math

Question 12

Which TWO statements about namespace packages are true?

Accepted Answer

They are supported in Python 3.3 and later.. Namespace packages were introduced in Python 3.3 via PEP 420. They allow a package to be split across multiple directories on sys.path without requiring an __init__.py file, enabling logical grouping of subpackages from different locations.

Answer

They are automatically created when a directory containing .py files is added to sys.path.

Answer

They can only contain __init__.py files.

Answer

They require an __init__.py file.

Question 13

Which THREE factors can cause an 'ImportError' when trying to import a module?

Accepted Answer

The module is a C extension that fails to load.. If a module is a C extension (e.g., a .so or .pyd file) and it fails to load due to missing dependencies, incompatible architecture, or a linking error, Python raises an ImportError. This is distinct from a syntax error in Python source code, which would raise a SyntaxError, not an ImportError.

Answer

The module file has a syntax error.

Answer

The module's __init__.py is empty.

Question 14

Which TWO of the following are valid ways to import specific names from a module?

Accepted Answer

from module import name1, name2. The `from module import name1, name2` syntax allows importing specific names from a module directly into the current namespace. Option C is also correct because `from module import name as alias` provides the same functionality while allowing you to rename the imported name to avoid naming conflicts.

Answer

from module import * (only names listed in __all__)

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import name1, name2 from module

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import module.name1

Question 15

Refer to the exhibit. A developer runs 'pip install pandas==2.0.0' but gets an error stating that the required version is not available. Which command should be used to list all available versions of pandas?

Accepted Answer

pip index versions pandas. `pip index versions pandas` is the command that queries the Python Package Index (PyPI) for all available versions of the specified package. This command was introduced in pip 21.1 and is the proper way to list version history without attempting to install.

Answer

pip search pandas

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pip show pandas

Answer

pip list --all pandas