writing serial port data to the gzip file

[Petr Jakes]

I am trying to save data it is comming from the serial port continually
for some period.
(expect reading from serial port is 100% not a problem)
Following is an example of the code I am trying to write. It works, but
it produce an empty gz file (0kB size) even I am sure I am getting data
from the serial port. It looks like g.close() does not close the gz
file.
I was reading in the doc:

Calling a GzipFile object's close() method does not close fileobj,
since you might wish to append more material after the compressed
data...

so I am completely lost now...

thanks for your comments.
Petr Jakes
==== snippet of the code  ====
def dataOnSerialPort():
    data=s.readLine()
    if data:
        return data
    else:
        return 0

while 1:
    g=gzip.GzipFile("/root/foofile.gz","w")
    while dataOnSerialPort():
        g.write(data)
    else: g.close()