#!/usr/bin/env python
# Wenchang Yang (wenchang@princeton.edu)
# Wed Oct 17 11:30:29 EDT 2018
import os, os.path, sys, glob

def run_shell(cmd):
    s = os.system(cmd)
    if s==0:
        print('[OK]:', cmd)
    else:
        print('[Failed]:', cmd)
        sys.exit()

ifiles = glob.glob('sst/by_year/*.nc')
ifiles.sort()
ofile = 'sst/sst.mon.avhrr-only-v2.1981-09.2018-09.nc'
for ifile in ifiles:
    tmpfile = 'tmp_' + ifile.split('/')[-1]
    cmd = f'cdo monmean {ifile} {tmpfile}'
    run_shell(cmd)

cmd = f'ncrcat tmp_*.nc {ofile}'
run_shell(cmd)

cmd = 'rm tmp_*.nc'
run_shell(cmd)