Fix dataloader filepath modification to perform replace only once and not for all occurences of string

[adumrewal]

Issue:

• Loading train/val data from parent/sibling folders
  • When you want to load training data in the following form: ./../../datasets/coco128/images/train/1.jpg
  • The current implementation replaces all occurrences of ./ with parent path

Fix:

• Replace only the first occurrence of ./ with parent path

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improvement in path handling for dataset loading in YOLOv5.

📊 Key Changes

• Adjusted the method that converts local paths to global paths within the dataset loader code.
• Changed string replacement logic to ensure it correctly transforms local paths starting with './' to their global equivalent by replacing only the first instance of './'.

🎯 Purpose & Impact

• Ensures robust and accurate file path conversion across different operating systems and environments.
• Users should experience more reliable dataset loading, especially when local paths are used.
• Reduces potential bugs related to path handling that could affect model training and evaluation. 🐛➡️🚫

[github-actions]

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[glenn-jocher]

@adumrewal first instance only, got it, very nice fix.

[glenn-jocher]

@adumrewal PR is merged. Thank you for your contributions to YOLOv5 🚀 and Vision AI ⭐