eccodes/examples/python/grib_get_keys.py

82 lines
2.1 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_get_keys
#
# Description: how to get values using keys from GRIB messages
#
from __future__ import print_function
import sys
import traceback
from eccodes import *
INPUT = "../../data/reduced_latlon_surface.grib1"
VERBOSE = 1 # verbose error reporting
def example():
f = open(INPUT, "rb")
keys = [
"Ni",
"Nj",
"latitudeOfFirstGridPointInDegrees",
"longitudeOfFirstGridPointInDegrees",
"latitudeOfLastGridPointInDegrees",
"longitudeOfLastGridPointInDegrees",
]
while 1:
gid = codes_grib_new_from_file(f)
if gid is None:
break
for key in keys:
try:
print(" %s: %s" % (key, codes_get(gid, key)))
except KeyValueNotFoundError as err:
# Full list of exceptions here:
# https://confluence.ecmwf.int/display/ECC/Python+exception+classes
print(' Key="%s" was not found: %s' % (key, err.msg))
except CodesInternalError as err:
print('Error with key="%s" : %s' % (key, err.msg))
print(
"There are %d values, average is %f, min is %f, max is %f"
% (
codes_get_size(gid, "values"),
codes_get(gid, "average"),
codes_get(gid, "min"),
codes_get(gid, "max"),
)
)
codes_release(gid)
f.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())