Task 1: Creating a Complete `pyproject.toml` Specification

Create a file named pyproject.toml inside your lesson_51 folder:

• Define build-system using Setuptools backend.
• Configure project metadata: name "sys-monitor-cli", version "1.0.0", description, and Python requirements (>=3.10).
• Add a global script entry point: sys-mon = "sys_monitor.cli:main".

Task 2: Pattern-Matched CLI Sub-command Processor

Create a script named cli_subcommands_task.py:

• Build an argparse parser with two sub-commands: create (username: str, role: str) and delete (username: str).
• Write a match-case dispatcher accepting the parsed Namespace object:
  • case Namespace(subcommand="create", username=u, role=r) → Return confirmation string.
  • case Namespace(subcommand="delete", username=u) → Return deletion warning string.
  • case _ → Return error string.
• Simulate execution calls for both sub-commands and print output strings.

Task 3: Master Review Capstone Project — Production Enterprise Deployable CLI Package Engine (`enterprise_packaging_os.py`)

Create a script named enterprise_packaging_os.py inside your lesson_51 folder. This assignment tests and integrates **ALL concepts learned across Lessons 1 through 51**.

Project Architectural Requirements Specification:

1. Packaging, CLI Tools & Distribution Architecture (Lesson 51):
   • Implement complete argparse argument parsing with sub-commands, optional flags, and custom validation.
   • Provide a programmatically generated pyproject.toml configuration string ready for distribution.
   • Structure the main execution as a global CLI entry point targetable via [project.scripts].
2. Clean Code, Documentation & Refactoring (Lesson 50):
   • Apply SOLID principles, DRY, and Google Style Docstrings across all functions and classes.
3. Debugging, Formatting & Linting (Lesson 49):
   • Ensure 100% PEP 8 compliance, strict type hinting, and zero linter warnings.
4. Testing & Quality Assurance (Lessons 47-48):
   • Include unit tests verified via pytest fixtures and unittest.mock.
5. Asyncio & Concurrency Integration (Lessons 45-46):
   • Incorporate asynchronous execution loops and TaskGroups for parallel service audits.
6. Temporal & RegEx Text Processing (Lessons 43-44):
   • Parse UTC-aware timestamps using datetime and zoneinfo.ZoneInfo.
   • Pre-compile RegEx patterns with Named Groups for parsing package version strings.
7. Type Hints, Generics & Static Safety (Lesson 42):
   • Apply explicit modern type annotations (X | Y, list[str], dict[str, Any]) throughout all functions and classes.
8. Metaprogramming, Closures & Decorators (Lessons 40-41):
   • Build function factories and 3-level configurable decorators with @functools.wraps.
9. Iterators & Generators (Lesson 39):
   • Implement generator functions streaming codebase audit lines lazily with $O(1)$ memory.
10. Full OOP Architecture (Lessons 32-38):
    • Define abstract base class BasePackageService(ABC) and concrete Data Classes PackageMetadata and CLIRecord.
    • Build composite manager EnterprisePackagingOS composing storage drivers and custom context managers.
11. Observability & Fault Tolerance (Lessons 29-31):
    • Set up multi-handler logging to console and packaging_os.log file.
    • Incorporate developer assertions (assert) verifying invariant bounds.
    • Define custom exception hierarchy (PackagingOSError, DistributionBuildError).
12. Context Managers & Persistence Layer (Lessons 27-30):
    • Use custom class-based context manager PackageVaultLock to manage database lock files.
    • Persist JSON records to packaging_db.json and export CSV audit reports to dist_audit.csv using pathlib.Path.
13. Nested Collections & Comprehensions (Lessons 21-26):
    • Maintain in-memory registry dictionaries mapping IDs to Data Class Instances.
    • Use List and Dictionary Comprehensions to clean and transform records.
14. Advanced Function Parameters & Scope (Lessons 15-17):
    • Structure logic into pure modular functions with type hints, docstrings, early return Guard Clauses, and *args / **kwargs logging.
15. Indefinite & Definite Loops (Lessons 13-14):
    • Run the interactive CLI interface inside a continuous while True menu loop.
    • Iterate through output reports using for loops with enumerate() and .items().
16. Pattern Matching CLI Dispatcher (Lesson 12):
    • Process user CLI command tokens inside a match-case block with packaging match guards:
      • case ["BUILD", "DIST", pkg_name] → Execute packaging build sequence and output distribution filenames.
      • case ["PUBLISH", "TESTPYPI", pkg_name] → Simulate twine upload pipeline with exception handling.
      • case ["AUDIT", "CLI"] → Inspect registered CLI entry points using match-case dispatcher.
      • case ["EXPORT", "CSV"] → Export package audit metrics to CSV.
      • case ["EXIT" | "QUIT"] → Terminate session safely using a sentinel flag.
      • case _ → Output command error message.
17. Conditionals, Formatting & Foundations (Lessons 1-11):
    • Sanitize all inputs using .strip() and .upper().
    • Format tabular reports using f-strings with field width alignment specifiers (:<15, :>10) and clear visual borders.