Adapt codebase from OpenAI Python 0.28.1 to 1.x

[xcvil]

Summary

This merge request updates the codebase (case 1) from OpenAI Python 0.28.x to OpenAI Python 1.x. The transition ensures that the project remains up-to-date and compatible with the latest OpenAI APIs.

Changes

• Initialized the OpenAI CLIENT object as a global variable to streamline API calls.
• Updated all instances of embeddings and chat.completions methods to their new API signatures.
• Added load_dotenv() before os.getenv() to ensure environment variables are loaded correctly.

Testing

I re-run to ensure that the updated methods work correctly with OpenAI Python 1.x.

Thank you for reviewing this merge request. Your feedback is appreciated.

[bstollnitz]

Thanks for your contribution, Xiaochen! I'm taking this year off to travel, so I don't plan to update my blog post for now. However, I've added a link to this PR in the repo's README file so that others can benefit from your work.

[xcvil]

Thanks for your contribution, Xiaochen! I'm taking this year off to travel, so I don't plan to update my blog post for now. However, I've added a link to this PR in the repo's README file so that others can benefit from your work.

Thanks a lot Beatriz! Hope you enjoy your holiday!