PCPP1 Best Practices And Coding Conventions — Timed 15 Questions

Question 1

According to PEP 257, what is the standard format for a single-line docstring?

Accepted Answer

Use triple quotes and keep the summary on the same line, ending with a period.. A single-line docstring should be on the same line as the opening triple quotes, ending with a period.

Answer

Use a single quote for the entire block.

Answer

The docstring should span three lines including the summary.

Answer

The summary should start on the next line.

Question 2

When naming a constant in Python, which convention does PEP 8 recommend?

Accepted Answer

UPPER_CASE_WITH_UNDERSCORES.. Constants should be named using all capital letters with underscores to separate words.

Answer

PascalCase.

Answer

snake_case.

Answer

CamelCase.

Question 3

Which practice is recommended when dealing with 'bare' except clauses in Python?

Accepted Answer

Always specify the exception type you intend to catch.. Bare 'except:' clauses catch SystemExit and KeyboardInterrupt, which can prevent the user from stopping a program.

Answer

Use bare 'except:' for performance optimization.

Answer

Use 'except Exception:' as the standard catch-all.

Answer

Use 'except:' but log the error immediately.

Question 4

You are debugging a legacy application and need to ensure that resources like file handles are always closed. Which construct is preferred?

Accepted Answer

Use a context manager with the 'with' statement.. The 'with' statement (context manager) ensures that cleanup code is executed even if an exception occurs.

Answer

Wrap the file operation in a try-except block.

Answer

Manually call file.close() in a finally block.

Answer

Rely on the garbage collector to close the handle.

Question 5

You are writing a library that expects a custom exception. Which practice aligns best with Python's exception handling hierarchy?

Accepted Answer

Inherit from Exception.. Custom exceptions should inherit from the built-in Exception class to ensure they are catchable by standard error handlers.

Answer

Use a mixin class without inheritance.

Answer

Inherit from StandardError.

Answer

Inherit from BaseException.

Question 6

When implementing secure coding practices in a web-facing Python application, how should you handle raw user input to prevent command injection?

Accepted Answer

Pass input arguments as a list to subprocess.run(args, shell=False).. Using the 'subprocess' module with 'shell=False' (the default) prevents the shell from interpreting user-provided strings as commands.

Answer

Pass the entire input string to os.system().

Answer

Concatenate the input string into a shell command for execution.

Answer

Sanitize input using a custom regex to remove special characters.

Question 7

When documenting a complex function, which approach is most compliant with Google Style Python Docstrings regarding parameter types?

Accepted Answer

Use the 'Args:' section followed by the parameter name, type, and description.. Google Style requires explicit listing of types in the Args section to improve readability for static analysis tools.

Answer

Embed the types directly in the function name.

Answer

Include type hints in the docstring but omit them from the function signature.

Answer

Avoid documenting types to prevent redundancy with type hints.

Question 8

In a team environment, which PEP 8 guideline should be applied to maintain consistent indentation when mixing spaces and tabs?

Accepted Answer

Use spaces exclusively for indentation.. PEP 8 states that spaces are the preferred indentation method over tabs to ensure cross-platform consistency.

Answer

Use tabs exclusively, as they are more efficient for file size.

Answer

Always use a combination of tabs and spaces to allow personal editor configuration.

Answer

Default to the indentation used by the first author of the module.

Question 9

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.

Answer

No limit.

Answer

120 characters.

Question 10

When designing a public API, how should you signal that a method is for internal use only?

Accepted Answer

By prepending a single underscore.. Prefixing a name with a single underscore is the conventional way to indicate internal use.

Answer

By raising a warning if called externally.

Answer

By adding a comment like '# INTERNAL'.

Answer

By using all caps.

Answer

By suffixing with an underscore.

Question 11

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 12

A script processes data from untrusted sources. Which technique best mitigates 'pickle' deserialization vulnerabilities?

Accepted Answer

Use an alternative format like JSON or XML for serialization.. The 'pickle' module is fundamentally insecure; using secure formats like JSON is the only way to avoid code injection during deserialization.

Answer

Only unpickle from files with a specific extension.

Answer

Wrap the unpickling in a try-except block.

Answer

Use 'pickle.load()' with a restricted whitelist of modules.

Question 13

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 14

When should you use absolute imports over relative imports in a large project?

Accepted Answer

Always, as they are PEP 8 recommended for clarity and robustness.. Absolute imports are recommended by PEP 8 because they are clearer and avoid ambiguity in complex package structures.

Answer

When the file is in the same directory.

Answer

Only if using Python 2.

Answer

When performance is the main priority.

Question 15

You need to ensure your code is readable by other Python developers. Which naming style should be used for variable names?

Accepted Answer

snake_case.. PEP 8 prescribes snake_case (lowercase with underscores) for variable and function names.

Answer

UPPER_SNAKE_CASE.

Answer

camelCase.

Answer

PascalCase.