Refactor __init__.py module to improve organization, readability and public API structure

[ilmoruuu]

Description:

This Pull Request introduces a structured refactoring of the src/flask/init.py file, aiming to improve internal organization and clarify the definition of the framework’s public API.
The modifications do not change runtime behavior but make the module more consistent, cleaner and aligned with architecture and style best practices.

Changes implemented:

• Fully reorganized imports, grouping them by source (standard library, third-party, internal modules).
• Removed redundant or unused imports.
• Improved all export structure to clearly define the public API.
• Added comments explaining the module’s responsibility as a high-level interface aggregator.
• Reduced visual noise and increased cohesion.
• Formatting and style adjustments aligned with tools like Flake8 and Pylint.

Motivation:

The init.py file acts as the main entry point for the Flask package, exposing the symbols developers interact with.
Before refactoring, the file contained inconsistencies in import ordering, export grouping and general structure.

These improvements:

• increase the clarity of the public API;
• make the codebase easier to navigate and maintain;
• reduce style violations (E401, F401, E302, etc.);
• decrease cognitive coupling and prepare the ground for deeper refactoring in critical modules such as app.py.
• Expected impact on metrics:
• Readability: improved through organized imports and structural cleanup.
• Cohesion: increased by keeping the module focused on API aggregation.
• Cognitive coupling: reduced due to clearer responsibilities.
• Flake8 violations: expected reduction in F401 (unused imports) and E501 (line length issues).

[davidism]

This is useless LLM junk. Do not waste maintainer time.

[ilmoruuu]

Hey! Sorry for the inconvenience. I was studying ways to improve Flask for a university assignment. I apologize again — it wasn’t my intention to disrupt your progress. Best regards, and once again, sorry about that.

[davidism]

Then your professor failed you in not teaching you how to contribute. Please tell your professor that maintainers want them to stop assigning this.