zipstream-ng is a modern and easy to use streamable zip file
generator. It can package and stream many files and folders on the
fly without needing temporary files or excessive memory.

Includes the ability to calculate the total size of the stream
before any data is actually added (provided no compression is used).
This makes it ideal for use in web applications since the total
size can be used to set the `Content-Length` header without having
to generate the entire file first.

Features:
 * Generates zip data on the fly as it's requested.
 * Can calculate the total size of the resulting zip file before generation even
   begins.
 * Flexible API: Typical use cases are simple, complicated ones are possible.
 * Supports zipping data from files, bytes, strings, and any other iterable
   objects.
 * Threadsafe: Won't mangle data if multiple threads concurrently add/read data
   to/from the same stream.
 * Includes a clone of Python's `http.server` module with zip support added.
   Try `python -m zipstream.server`.
 * Automatically uses Zip64 extensions, but only if they are required.
 * No external dependencies.