Modules and Packages

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?

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?

You are a DevOps engineer managing a Python application that consists of multiple microservices. One microservice, 'data_processor', imports a shared library 'common_lib' which is also used by other microservices. The shared library is developed in a separate repository and is installed via pip in each microservice's virtual environment as an editable package (pip install -e). Recently, you updated 'common_lib' with new functions, but when you redeploy 'data_processor' (by restarting the container), the new functions are not available; the old version is still used. The container uses a Docker image built from a requirements file that specifies 'common_lib' from a Git repository. You verify that the Git commit hash in the requirements file points to the latest version. What is the most likely cause and what is the correct course of action?

Which THREE of the following statements about Python's module search path are true?

A developer notices that a custom package 'mypackage' is not being found when importing, even though it is installed in the site-packages directory. The developer suspects a conflict with another package of the same name. Which command should the developer run to diagnose the location from which Python is importing the package?

A developer has a module 'config.py' with the following content: # config.py import os DATABASE_URL = os.getenv('DATABASE_URL', 'localhost') Another module 'app.py' imports config and uses DATABASE_URL. During testing, the environment variable is set correctly, but the import still uses the default value 'localhost'. What is the most likely reason?

Which TWO of the following are valid ways to import a function 'foo' from a module 'bar' that is located in a package 'mypackage'?

You are a developer for a data science team. The team uses a shared module 'utilities' located at /team/shared/utilities.py. This module is not part of any package, and they want to import it from various project scripts without copying the file. Some projects are in /home/user/proj_A/ and others in /var/data/proj_B/. Currently, each script manually adds /team/shared/ to sys.path using sys.path.insert(0, '/team/shared/'). This works but is repetitive. The team wants a cleaner solution that also works when the script is run from different working directories. They consider creating a package 'utilities' by adding an __init__.py to the directory and using relative imports. However, the module currently uses absolute imports for some external libraries. What is the best course of action to allow clean imports of utilities from any location while minimizing changes to the module itself?

Which TWO statements about the 'from package import *' statement are correct?

A user wants to ensure that a custom module 'mymod' located at '/home/user/custom' takes precedence over a standard library module with the same name. Which operation on sys.path should be performed?

Which THREE factors influence Python's module search path (sys.path)?

A Python script uses a third-party library 'requests'. The developer wants to ensure that the exact version 2.25.1 is installed in the project's environment. Which tool and command should be used?

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?

A team is using a shared Python environment where multiple projects have conflicting dependencies. Which approach is the best practice to isolate project dependencies?

You are developing a package 'analytics' that contains subpackages 'stats' and 'ml'. The __init__.py of 'analytics' imports a function 'normalize' from 'analytics.stats'. When a user runs `import analytics`, they get an ImportError. Which change ensures the package imports correctly?

A developer creates a package named 'mypkg' with an __init__.py file. Inside the package, there is a module 'utils.py'. Which of the following is the correct way to import the function 'helper' from 'utils' from outside the package?

Your company has two separate Python packages: 'app' and 'lib'. They are maintained by different teams. 'app' depends on 'lib', but 'lib' is still under development and its API changes frequently. To avoid breaking 'app', the team decides to use a virtual environment and install a specific version of 'lib'. However, during development, they need to test 'app' with the latest 'lib' changes from the Git repository. The current workflow is: (1) activate virtual env, (2) install 'lib' from local source using `pip install -e /path/to/lib`. This installs 'lib' as a development package. But one developer reports that after pulling latest 'lib' changes, importing 'lib' in 'app' still uses the old version even after re-running pip install -e. What is the most likely reason?

Refer to the exhibit. A script executes 'from mypackage import *'. Which functions are available in the global namespace?

A Python script imports the module 'my_module'. The developer wants to ensure that when the script is run directly, it executes a specific function, but when imported as a module, that function is not executed. Which code snippet achieves this?

A company has a large Python application that uses multiple packages from different directories. The application's main entry point is at /opt/app/main.py. There is a package 'common' located at /opt/app/common/ and another package 'services' at /opt/app/services/. Both packages have __init__.py files. Additionally, there is a third-party package 'utils' installed in the system site-packages. Recently, a developer added a new module 'helpers.py' to the 'common' package. When trying to import 'common.helpers' from a script inside 'services', an ImportError is raised: 'No module named common.helpers'. However, importing 'common' itself works. The sys.path includes /opt/app/ and the site-packages. What is the most likely cause of the import failure?

A developer creates a package 'mypackage' with the following structure: mypackage/ __init__.py module1.py module2.py The __init__.py contains: from mypackage.module1 import func1 from mypackage.module2 import func2 __all__ = ['func1', 'func2'] In a separate script, the developer writes: from mypackage import * print(func1()) This works as expected. However, when the developer runs the same script from a different directory (not the one containing mypackage), the import works but the script prints an error that func1 is not defined. What could be the problem?

Which TWO of the following statements about Python's `sys.path` are true?

A Python package 'mypackage' contains the following hierarchy: mypackage/ __init__.py subpackage1/ __init__.py module_a.py subpackage2/ __init__.py module_b.py From a script outside the package, a programmer writes: import mypackage.subpackage1.module_a Which statement is true about the import?

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

A Python script placed in /opt/myapp/script.py fails with ImportError when run from a cron job with the command: python /opt/myapp/script.py. The script works when run manually from the /opt/myapp/ directory. The script contains the line: from . import config. The config module is located in /opt/myapp/lib/config.py with an __init__.py in /opt/myapp/lib/. What is the most likely cause of the failure?

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?

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

A package 'pkg' is installed as an egg-link in development mode. Inside the package, there is a module 'submod.py' that uses relative imports. When a developer modifies 'submod.py', they find that changes are not always reflected on import. What is the most likely reason?

A developer installs a third-party package using pip, but when they try to import it in their script, Python raises a ModuleNotFoundError. The package is definitely installed (pip list shows it). What is the most likely cause?

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

Refer to the exhibit. Which of the following is the most likely cause of this error?

Refer to the exhibit. Given the project structure, which of the following import statements in main.py would cause an ImportError?

You are a Python developer working on a project with the following structure: myapp/ __init__.py main.py modules/ __init__.py utils.py helpers.py The file main.py contains: from modules import utils from modules import helpers utils.some_function() helpers.another_function() When you run main.py, you get an ImportError: No module named 'modules'. However, the modules directory exists and both __init__.py files are present. The directory myapp is not installed as a package; you are running main.py directly from the myapp directory. What is the most likely cause and how should you fix it?

You are a developer at a company that builds a data processing pipeline. The pipeline consists of several Python modules organized in a package called 'pipeline'. The package structure is: pipeline/ __init__.py load.py transform.py analyze.py The pipeline is deployed on a server where Python 3.8 is installed. The server also has a globally installed package called 'pipeline' (from a different project) in the site-packages directory. When you run your scripts that import 'pipeline', you get unexpected behavior because Python is importing the wrong package. You need to ensure that your local 'pipeline' package is used instead of the global one. You cannot uninstall the global package because it is used by another application. You have the following options: A) Modify the PYTHONPATH environment variable to include the directory containing your 'pipeline' package before the site-packages directory. B) Rename your local 'pipeline' package to something else and update all imports. C) Use a virtual environment specific to your project and install your package there. D) Add an __init__.py file with a special import hook to override the global package. Which course of action is the most appropriate and reliable?

You are developing a Python application that processes financial transactions. The application is structured as a package named `finance`. Inside `finance`, there are subpackages: `models`, `services`, and `utils`. The `services` subpackage contains a module `validator.py` that defines a function `validate_transaction()`. This function uses a helper function `check_amount()` defined in `utils.helpers`. The package is used by multiple other projects, and you want to ensure that importing `finance` does not accidentally expose internal helper functions. You also want to allow users to easily import the main validation function via `from finance import validate_transaction`. Which of the following approaches best achieves these goals?

A script runs: import sys; print(sys.path[0]). The output is an empty string. What does this indicate?

A team uses virtual environments to manage dependencies. They need to ensure that a script runs with the exact same module versions across different environments. Which approach is best?

A developer is writing a package that contains multiple modules. The package should allow users to import it directly and have all commonly used functions available at the package level. For example, after `import mypackage`, the user should be able to call `mypackage.func1()` without needing to import submodules. Which is the best way to achieve this?

Which THREE of the following statements about Python packages and modules are true?

A package 'mypackage' has subpackages 'sub1' and 'sub2'. In sub1/__init__.py, there is: from sub2 import helper. When importing mypackage, an ImportError occurs: No module named 'sub2'. What is the most likely cause?

Which TWO of the following are valid ways to import a module named 'math' and give it an alias 'm'?

A developer has two separate directories on sys.path: /home/user/libs and /opt/libs. Both directories contain a subdirectory 'mypackage' without an __init__.py file. The developer wants to import a module from 'mypackage' that exists only in one of the directories. What concept allows Python to treat these two directories as a single namespace package?

You maintain a Python library 'myutils' that is installed as a package in the system. The library has a submodule 'config' that reads configuration from a file. Recently, a user reported that after updating the library, their application still uses the old configuration values. They confirmed that the config file on disk has been updated. The library's __init__.py does: from .config import load_config. The user's application imports load_config from myutils and calls it each time they need configuration. What is the most likely cause of the issue?

A module 'shapes.py' defines several classes: Circle, Square, Triangle. The developer wants to allow users to import only Circle and Square when they use 'from shapes import *'. Which mechanism should be used?

A Python script is written to be used both as a standalone program and as an imported module. Which condition should the script use to execute code only when run directly?

A team is developing a large Python application with multiple modules. They encounter an ImportError when module A tries to import from module B, and module B tries to import from module A. What is the most likely cause and best practice to resolve this?

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