import os
import gzip

out_file = open('FOO.gz', 'wb')
print('out_file', out_file)
out_fd = out_file.fileno()
print('out_fd', out_fd)

fd_out_file = os.fdopen(out_fd, 'wb')
print('fd_out_file', fd_out_file)
print('fd_out_file.name', fd_out_file.name)

gz_out_file = gzip.GzipFile(fileobj=fd_out_file)
gz_out_file.write(b'FOO was here!')
gz_out_file.close()
fd_out_file.close()
out_file.close()