[Python-Dev] Request for Pronouncement: PEP 441 - Improving Python ZIP Application Support

[Paul Moore]

On 23 February 2015 at 19:22, Ethan Furman <ethan at stoneleaf.us> wrote:
> This could be a completely stupid question, but how does the zip file know where the individual files are?  More to the
> point, does the index work via relative or absolute offset?  If absolute, wouldn't the index have to be rewritten if the
> zip portion of the file moves?

Essentially the index is stored at the *end* of the file, and contains
relative offsets to all the files. Gory details at
https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT
Paul