rcmet/src/main/python/rcmes/services/list_vars_in_file.py

#
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#  The ASF licenses this file to You under the Apache License, Version 2.0
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#      http://www.apache.org/licenses/LICENSE-2.0
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#!/usr/local/bin/python
"""
 Small command line utility to list the variables contained within a model file.

  This script should be run from the command line (i.e. not called from within python)

       Input: 
               -filename

       Output: 
               -list of variable names in file

       (NB. all printed to standar output)

       Peter Lean   February 2011

 WEBSERVICE PLAN

    URL:  localhost:9999/list_vars/:filename    (full file path plus file name)
    Example:  localhost:9999/list/vars/"/usr/local/wrm/modeldata/wrf.nc"

    Return:  JSON Array of Variable Names
    Example:  { "variables": [ "time_bnds", "tas", "level", "lon", "time", "lat" ] }
"""

import sys
import netCDF4
import bottle
from bottle import request
import json
#filename = sys.argv[1]


@bottle.route('/list/vars/:filename#".*"#')
def list_vars(filename):
    success = 0
    filename = filename.strip('"')
    print filename + ' is filename variable'
    try:
      f = netCDF4.Dataset(filename, mode='r')
      success = 1
    except:
      print 'Error_reading_file '+filename
    
    if success:  #make some json
      var_name_list = json.dumps({'variables':f.variables.keys().encode() }, \
                                 sort_keys=True, indent=2)
      if (request.query.callback):
          return "%s(%s)" % (request.query.callback, var_name_list)
      return var_name_list
  
    else:
      failRet = "{\"FAIL\": \""+filename+"\"}"
      if (request.query.callback):
          return "%s(%s)" % (request.query.callback, failRet)
      return failRet