How to make indexes in pygrib (grib2 files)?

I'm trying to read grib2 file using pygrib from here. But it takes more than 4-5 hours to read the entire 120 files. So I tried making indexes to read the file faster. Whenever I try to make a index on the value key, I get this error:

msgs = grbindx.select(level = 0, typeOfLevel = "surface",parameterName = "values")
File "pygrib.pyx", line 2003, in pygrib.index.select (pygrib.c:30731)
ValueError: no matches found

Here's my code:

    #grb = grbs.select(name='UV index')[0]
    #uvi surface 0
    grbindx = pygrib.index('uv.t12z.grbf64.grib2','typeOfLevel','level','parameterName')
    msgs = grbindx.select(level = 0, typeOfLevel = "surface",parameterName = "values")
    print msgs.keys

Can anyone explain what am I doing wrong ?

Solution

grib_ls shows on file of such type:

edition      centre       date         dataType     gridType     stepRange    typeOfLevel  level        shortName    packingType  
2            kwbc         20160612     fc           regular_ll   12           surface      0            uvi          grid_jpeg   
1 of 1 grib messages in uv.t12z.grbf12.grib2

Therefore, try to read like here:

   grbindx = pygrib.index('uv.t12z.grbf64.grib2','typeOfLevel','level','shortName')
    msgs = grbindx.select(level = 0, typeOfLevel = "surface",shortName = "uvi")
    print msgs

However, I guess, you will not get speed-up because of this file has only one record.