Course Video Downloader Script

I need a small, reliable script that logs in to my subscription-based learning platform, fetches every lecture in a chosen course, and saves each video locally as MP4. When subtitles are available they should be downloaded too and kept in sync; if a lecture has no subs, the script can simply skip that step.

File organisation matters: after the download finishes I want a neatly numbered sequence (01, 02, 03…) so it plays back in the exact lecture order without extra manual renaming. A simple folder per course is fine; the key is that the individual files follow the lecture sequence.

Please build this in whatever language or toolchain you’re most comfortable with—python + yt-dlp, node, or a lightweight CLI utility—so long as it runs on Windows and macOS and includes clear setup instructions. Credentials will be provided for testing; protect them in the code (env vars or config file, not hard-coded).

Deliverables
• Source code with concise README covering prerequisites, setup, and example usage
• A brief note on how the script detects and grabs subtitles only when they exist
• One test run showing the lecture-sequence naming working correctly

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