eccodes/examples/python/grib_set_keys.py

91 lines
2.7 KiB
Python

# (C) Copyright 2005- ECMWF.
#
# This software is licensed under the terms of the Apache Licence Version 2.0
# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
#
# In applying this licence, ECMWF does not waive the privileges and immunities
# granted to it by virtue of its status as an intergovernmental organisation
# nor does it submit to any jurisdiction.
# Python Implementation: grib_set_keys
#
# Description: how to set key values in GRIB messages
#
import sys
import traceback
from collections import OrderedDict
from datetime import date
from eccodes import *
INPUT = "../../data/regular_latlon_surface_constant.grib1"
OUTPUT = "out.set.grib"
VERBOSE = 1 # verbose error reporting
def example():
fin = open(INPUT, "rb")
fout = open(OUTPUT, "wb")
gid = codes_grib_new_from_file(fin)
dt = date.today()
today = "%d%02d%02d" % (dt.year, dt.month, dt.day)
codes_set(gid, "dataDate", int(today))
codes_set(gid, "centre", 80)
centreIntVal = codes_get_array(gid, "centre", int)
centreStrVal = codes_get_array(gid, "centre", str)
dateStrVal = codes_get_array(gid, "dataDate", str)
assert centreIntVal[0] == 80
assert centreStrVal[0] == "cnmc"
assert dateStrVal[0] == today
print("get centre as an integer - centre = %d" % centreIntVal[0])
print("get centre as a string - centre = %s" % centreStrVal[0])
print("get date as a string - date = %s" % dateStrVal[0])
# Now do the same but using set_key_vals, setting keys all at once
print("set keys using one long comma-separated string...")
codes_set_key_vals(gid, "level=1,centre=98")
assert codes_get(gid, "centre", str) == "ecmf"
assert codes_get(gid, "level", int) == 1
print("set keys using a list of strings...")
codes_set_key_vals(gid, ["level=2", "centre=kwbc"])
assert codes_get(gid, "centre", int) == 7
assert codes_get(gid, "level", int) == 2
print("set keys using a dictionary (order not as specified!)...")
codes_set_key_vals(gid, {"level": 3, "centre": 84})
assert codes_get(gid, "centre", str) == "lfpw"
assert codes_get(gid, "level", int) == 3
print("set keys using an ordered dictionary...")
codes_set_key_vals(gid, OrderedDict([("level", 3), ("centre", 84)]))
assert codes_get(gid, "centre", str) == "lfpw"
assert codes_get(gid, "level", int) == 3
codes_gts_header(True)
codes_gts_header(False)
codes_write(gid, fout)
codes_release(gid)
fin.close()
fout.close()
def main():
try:
example()
except CodesInternalError as err:
if VERBOSE:
traceback.print_exc(file=sys.stderr)
else:
sys.stderr.write(err.msg + "\n")
return 1
if __name__ == "__main__":
sys.exit(main())