Attempting streaming gzip compression.

gzip.py

import zlib


def yield_uncompressed_bytes():
    # In a real case, would yield bytes pulled from the filesystem or the network
    chunk = b'*' * 10
    for _ in range(0, 5):
        print('In: ', len(chunk))
        yield chunk


def yield_compressed_bytes(_uncompressed_bytes):
    compress_obj = zlib.compressobj()
    for chunk in _uncompressed_bytes:
        if compressed_bytes := compress_obj.compress(chunk):
            yield compressed_bytes

    if compressed_bytes := compress_obj.flush():
        yield compressed_bytes


uncompressed_bytes = yield_uncompressed_bytes()
compressed_bytes = yield_compressed_bytes(uncompressed_bytes)

with open("test2.gz", "wb") as f_out:
    for chunk in compressed_bytes:
        # In a real case, could save to the filesystem, or send over the network
        # print('Out:', len(chunk))
        f_out.write(chunk)

# doesn't recognize the result as an archive