Python's zipfile.ZipFile class defaults to using compression =
    ZIP_STORED (i.e. no compression). The other option, ZIP_DEFLATE,
    requires that zlib is installed. If you want to set the compression on
    the zip file, you need to create it beforehand and then pass it in to
    export_csv_zip using the zip option:

    hisSelect = SalaryHistory.select()
    salSelect = Sales.select()
    myZip = zipfile.ZipFile ("C:/myFile.zip, mode='w', compression=compression)
    export_csv_zip([hisSelect, salSelect], zip=myZip)

    [This code is untested. :]

 
Thanx!!
This actually works.
Petr