Writing then reading in-memory bytes (BytesIO) gives a blank result

How about we write and read gzip content in the same context like this?

#!/usr/bin/env python

from io import BytesIO
import gzip

content = b"does it work"

# write bytes to zip file in memory
gzipped_content = None
with BytesIO() as myio:
    with gzip.GzipFile(fileobj=myio, mode='wb') as g:
        g.write(content)
    gzipped_content = myio.getvalue()

print(gzipped_content)
print(content == gzip.decompress(gzipped_content))

You need to seek back to the beginning of the file after writing the initial in memory file...

myio.seek(0)