PCAP Modules and Packages Practice Test 2 — 15 Questions

Question 1

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 2

A script is located in the parent directory of a package named 'mypackage'. Which import statement correctly imports the 'foo' module from the 'mypackage' package?

Accepted Answer

from mypackage import foo. Both 'from mypackage import foo' and 'import mypackage.foo' correctly import the foo module from the package. The first binds the name foo directly; the second binds the package name mypackage and allows access to the submodule as mypackage.foo. Option C is invalid because relative imports require a package context, and option D has incorrect syntax.

Answer

from .mypackage import foo

Answer

import foo from mypackage

Question 3

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 4

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 5

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 6

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__)

Answer

import name1, name2 from module

Answer

import module.name1

Question 7

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

Answer

pip show pandas

Answer

pip list --all pandas

Question 8

A developer has a project structure with 'my_package/' containing '__init__.py', 'module_a.py', and 'sub_package/' (with its own '__init__.py'). They want to import function 'foo' from 'module_a' inside a script in 'sub_package' using a relative import. Which statement is correct?

Accepted Answer

from ..module_a import foo. The script is inside 'sub_package/', which is one directory level below 'my_package/'. To import from 'module_a' (located in the parent package 'my_package'), a relative import uses '..' to go up one package level, then specifies the module name. Thus, 'from ..module_a import foo' correctly navigates the package hierarchy.

Answer

from .module_a import foo

Answer

from my_package.module_a import foo

Answer

from ..my_package.module_a import foo

Question 9

A developer is creating a Python package named 'utils' and wants to control what is imported when a user writes 'from utils import *'. Which file and variable should be defined?

Accepted Answer

Define __all__ = ['mod1', 'mod2'] in '__init__.py' of the 'utils' package.. In Python, the `__all__` variable in the `__init__.py` file of a package explicitly defines the list of module names that are exported when a user writes `from utils import *`. This controls the public API of the package and prevents unintended internal modules from being imported.

Answer

Define __all__ as a function that returns the list of modules in '__init__.py'.

Answer

Set the __all__ variable in the script that imports the package.

Answer

Define __all__ as a list of module objects in the main module 'utils.py'.

Question 10

A Python application needs to load a configuration file that should be placed in the same directory as the main script. The developer uses the __file__ attribute to get the script's path. Which expression correctly obtains the directory containing the main script?

Accepted Answer

os.path.dirname(os.path.realpath(__file__)). os.path.realpath(__file__) returns the canonical path of the script, resolving any symbolic links. This ensures that the directory returned is the one where the actual script file resides, which is where the configuration file should be placed. os.path.abspath(__file__) only makes a relative path absolute and normalizes it, but it does not follow symlinks; if the script is executed via a symlink, abspath returns the symlink's directory, which may not contain the configuration file.

Answer

os.path.dirname(os.path.abspath(__file__))

Answer

os.getcwd()

Answer

os.path.abspath(__file__)

Question 11

A package 'mypkg' has the following structure:
mypkg/
  __init__.py
  submod1.py
  submod2.py
The __init__.py file contains: from . import submod1, submod2. A user runs 'import mypkg' and then 'mypkg.submod1.func()'. However, the user got an AttributeError. What is the most likely cause?

Accepted Answer

The submod1 module does not define a function named 'func'.. The AttributeError indicates that the attribute 'func' was not found on the module object 'submod1'. Since the import statement in __init__.py correctly makes submod1 accessible as mypkg.submod1, the only remaining reason for the error is that submod1.py does not define a function named 'func'. The import mechanism itself is working as intended.

Answer

submod1 is actually a package, not a module, so it cannot be called with 'func()'.

Answer

The __init__.py should use absolute imports like 'import mypkg.submod1' to make submod1 accessible.

Answer

The user must also run 'from mypkg import submod1' before accessing submod1.

Question 12

A developer wants to use a function 'calculate' from a module 'math_ops' that is located in a sibling directory '../shared/' relative to the current script. What is the correct way to import it using an absolute import assuming the shared directory is a package with __init__.py and the project root is in sys.path?

Accepted Answer

from shared.math_ops import calculate. Absolute imports in Python use the project root as the base, not relative paths. Since the project root is in sys.path, 'from shared.math_ops import calculate' directly references the 'shared' package at the top level, regardless of the current script's location. This is the standard absolute import syntax as defined in PEP 328.

Answer

from .shared.math_ops import calculate

Answer

from ..shared.math_ops import calculate

Answer

import ..shared.math_ops

Question 13

A Python package 'analytics' contains a subpackage 'models' with module 'regression.py'. Inside 'regression.py', there is a function 'linear_fit' that depends on 'numpy'. The developer wants to ensure that 'numpy' is imported only once and available throughout the package. Where should the import 'import numpy as np' be placed?

Accepted Answer

In each module that uses numpy, add 'import numpy as np'.. To use numpy in regression.py, that module must have its own import statement, e.g., 'import numpy as np'. Python caches modules in sys.modules, so loading happens only once regardless of where the import statement appears. Thus, repeating 'import numpy as np' in each module that needs it is both correct and efficient, and it respects namespace isolation.

Answer

In the '__init__.py' of the 'models' subpackage.

Answer

In the '__init__.py' of the 'analytics' top-level package.

Answer

In a separate file 'common_imports.py' and import that file everywhere.

Question 14

A developer runs the following code in a script that is not part of a package:
import sys
sys.path.insert(0, '/custom/path')
import mymodule
print(mymodule.__name__)
What is the output if 'mymodule' is found at '/custom/path/mymodule.py'?

Accepted Answer

mymodule. When a module is imported, Python assigns the `__name__` attribute to the module's name as a string (e.g., 'mymodule'), not the filename with extension. Since the script is not part of a package and the module is found at a custom path, `mymodule.__name__` is simply 'mymodule'.

Answer

mymodule.py

Answer

__main__

Answer

/custom/path/mymodule.py

Question 15

Which TWO of the following are valid uses for the '__name__' variable in a Python module?

Accepted Answer

To check if the module is being run as the main program.. The '__name__' variable is set to the string '__main__' when the module is executed directly as the main program (e.g., via 'python module.py'). This allows a module to include code that runs only when it is the entry point, not when it is imported by another module. The check is typically done with 'if __name__ == "__main__":'.

Answer

To get the file path of the module.

Answer

To control which names are exported when using 'from module import *'.

Answer

To determine which module imported it.