PCAP-31-03 1.5 Create and Use User-Defined Modules and Packages PCAP-31 Practice Questions (Page 3)

Questions 11–15

1. 11application · easy

   A developer is investigating why importing a large module `dataprocess.py` is slow on the first import but faster on subsequent imports in the same session. The developer notices a `__pycache__` directory was created. What is the most accurate explanation for the speed difference?

   • AThe first import downloads the module from the internet, and subsequent imports use the local copy.
   • BThe first import compiles the source to bytecode and stores it in `__pycache__`; subsequent imports load the cached bytecode instead of recompiling.
   • CThe first import adds the module to `sys.path`, making subsequent imports faster.
   • DThe first import copies the source code into memory, and subsequent imports read from the copy.
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2. 12application · easy

   A developer notices that after importing a custom module `data_utils.py` multiple times in a single session, a `__pycache__` directory appears in the same folder. The developer wants to understand why the directory was created and whether it is safe to delete. Which statement accurately describes the purpose of `__pycache__`?

   • AIt stores a copy of the original source code so that the module can be imported even if the `.py` file is deleted.
   • BIt stores compiled bytecode (`.pyc` files) so that subsequent imports of the module load faster, and it is safe to delete because Python will regenerate it.
   • CIt is required for a directory to be treated as a package and must not be deleted.
   • DIt stores a log of all import statements executed in the current session for debugging purposes.
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4. 13application · medium

   A developer has the following directory structure on disk: ``` project/ main.py utils/ helpers.py ``` The `utils` directory does NOT contain an `__init__.py` file. The developer wants to import `helpers` from `main.py`. Which import statement will work?

   • A`import sys; sys.path.append('utils'); import helpers`
   • B`from . import helpers`
   • C`import utils.helpers`
   • D`from utils import helpers`
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5. 14foundation · easy

   Which statement about private variables in a Python module is true?

   • AThey are accessible only through a special `getattr` function.
   • BThey are automatically excluded from the module's namespace when imported.
   • CThey are a convention that signals the name is for internal use, but they are still accessible.
   • DThey are completely inaccessible from outside the module.
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6. 15foundation · easy

   What is the purpose of the `if __name__ == '__main__':` idiom in a Python file?

   • ATo automatically export all functions in the file.
   • BTo ensure the code inside the block runs only when the file is executed directly as a script.
   • CTo make the file run faster when imported.
   • DTo prevent the file from being imported by other modules.
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