#!/usr/bin/env python3
# this version uses regular expressions
# same order as original grib file
import pywgrib2_s
in_file='a.grb'
out='a_subset_2.grb'
#
# inv='a.inv'
inv='@mem:0'
print('start mk_inv')
ierr = pywgrib2_s.mk_inv(in_file, inv)
print('mk_inv ierr=',ierr)
# search strings have to start/end with colons
# don't want '50 mb' to match '850 mb'
# or 'TMP' to match 'VTMP'
nmatch = pywgrib2_s.inq(in_file,':(TMP:2 m above ground|PRATE|UGRD:10 m above ground):',
inv=inv, Regex=True, grib=out)
print("done count=",nmatch," out=",out)