eccodes/examples/python/bufr_keys_iterator.py

85 lines
2.0 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: bufr_keys_iterator
#
# Description: Example on how to use keys_iterator functions and the
# codes_bufr_keys_iterator structure to get all the available
# keys in a BUFR message.
import sys
import traceback
from eccodes import *
VERBOSE = 1 # verbose error reporting
def example(INPUT):
# open bufr file
f = open(INPUT, "rb")
cnt = 0
subset = 0
# loop for the messages in the file
while 1:
# get handle for message
bufr = codes_bufr_new_from_file(f)
if bufr is None:
break
print("message: %s" % cnt)
# we need to instruct ecCodes to expand all the descriptors
# i.e. unpack the data values
codes_set(bufr, "unpack", 1)
# get BUFR key iterator
iterid = codes_bufr_keys_iterator_new(bufr)
# loop over the keys
while codes_bufr_keys_iterator_next(iterid):
# print key name
keyname = codes_bufr_keys_iterator_get_name(iterid)
if keyname == "subsetNumber":
subset += 1
print(" Subset: %d" % subset)
else:
print(" %s" % keyname)
# delete the key iterator
codes_bufr_keys_iterator_delete(iterid)
cnt += 1
# delete handle
codes_release(bufr)
# close the file
f.close()
def main():
try:
example(sys.argv[1])
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())