precommit: Black

[Borda]

use Black as default codebase formatting
Resolves #4983

This PR defines Black as pre-commit hook and lets the bot fix it... 🐰

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

WARNING ⚠️ this PR is very large, summary may not cover all changes.

🌟 Summary

Summarization of GitHub Pull Request in Ultralytics YOLOv5 repository with code diffs.

📊 Key Changes

• Code formatting improved with stylistic changes such as indentation, quotation adjustments, and spacing for better readability.
• Type hinting improved for better code clarity in function arguments.
• Updated console message text to be enclosed in quotes for improved clarity and consistency.
• Minor syntax improvements, such as removing unnecessary list creation and redundant lambda variable declarations.

🎯 Purpose & Impact

• 🔍 Code Readability: The reformatting improves code readability, making it easier for developers to understand the codebase.
• 👁️ Visibility: Explicit type-hints offer better visibility of expected function inputs, enhancing maintainability.
• 📈 Consistency: Consistent use of quotations and message formatting promotes uniform coding standards.
• ✨ Quality: Small syntax improvements add up to a general increase in code quality.

[glenn-jocher]

@Borda thanks for the PR! I think Black may be a bit too much for us right now. I actually do like some of the updates, in particular the 0. -> 0.0, and the 1E6 -> 1e6, but others I'd rather skip like listing imports one per line. Is there a way to enable only certain changes, or is Black an all-or-none linter?

In the meantime I made a new PR to fix as many 0. -> 0.0 as I could fine using PyCharm search and replace in #5491.

[Borda]

well, an alternative is YAPF (#5494), you can check how it looks like in my personal repo:
https://github.com/Borda/pyImSegm/blob/c52e709f9fcd90bcc6ab06e515685fd4c4e6c301/setup.cfg#L43-L52

there is also just autopep8 fixer, https://pypi.org/project/autopep8/
I made it as a draft just to open discussion :]

[glenn-jocher]

@Borda closing this to focus on yapf and readme per our convo. Thank you for your contributions to YOLOv5 🚀 and Vision AI ⭐