[Python] How can I resume downloading file from where it left off without using the HTTP Range...

I’m working on a downloader in Python using requests. My goal is to resume downloading large files after an interruption (e.g., crash or network failure).

✅ My constraints:

I already have part of the file saved locally (on disk or in memory) — say the first N MB of the file.

I want to resume the download at the correct position (after N MB) without re-downloading the bytes I already have.

I want to avoid using the HTTP Range header (assume the server doesn’t support it or I can’t use it).

I want to save bandwidth, not just skip writing already-downloaded data.

My question:


➡ Is there any way to resume download without re-downloading already received bytes AND without using the Range header?

➡ If not, what’s the best way to design this to save bandwidth under these constraints?

Continue reading...