#IOOS #MMI Example Python code to extract controlled vocabulary term information from MMI-hosted vocabularies.

mmi_term_testing.ipynb

{
 "metadata": {
  "name": "Accessing IOOS MMI Vocabulary Terms"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": "Accessing and Validating IOOS MMI Vocabulary Terms"
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "import json\nimport requests",
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "def get_term_ontmeta_jsonurl(termjsonurl):\n    \"\"\" \n    Pass a complete URL for the json response corresponding to an ontology term.\n    It can be from any ontology engine as long as the json is similar to MMI's.\n    eg: 'http://mmisw.org/ont/cf/parameter/wind_speed.json'\n    Parses the json response to return regularized dictionaries.\n    \"\"\"\n    \n    # This is probably not applicable to other ontology repos beyond MMI...\n    param_jsonstr = requests.get(termjsonurl).content\n    # Validate the term URL\n    if param_jsonstr == '[]':  # term URL does not exist; term is invalid\n        return (None, None)\n    \n    #param_jsonstr = urllib2.urlopen(termjsonurl).read()    \n    param_json = json.loads(param_jsonstr)\n    param_extract_all_dct = dict([(param_el[1].split('/')[-1][:-1], param_el[2]) \n                                  for param_el in param_json])\n    \n    # Add handling of more IOOS vocabularies, as needed\n    if 'cf/parameter' in termjsonurl:\n        param_extract_dct = {'vocabulary': 'cf/parameter',\n                             'definition': param_extract_all_dct['core#definition'],\n                             'units':      param_extract_all_dct['canonical_units'],\n                             'units_type': 'canonical units', \n                            }\n    elif 'ioos/parameter' in termjsonurl:\n        param_extract_dct = {'vocabulary': 'ioos/parameter',\n                             'definition': param_extract_all_dct['Definition'],\n                             'units':      param_extract_all_dct['Units'], \n                             'units_type': 'example or common units', \n                            }\n    else:\n        param_extract_dct = param_extract_all_dct\n    \n    return (param_extract_all_dct, param_extract_dct)",
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "# Test terms (as json URL end points)\nws_ioos = 'http://mmisw.org/ont/ioos/parameter/wind_speed.json'\nws_cf = 'http://mmisw.org/ont/cf/parameter/wind_speed.json'",
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "get_term_ontmeta_jsonurl(ws_ioos)",
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 4,
       "text": "({u'22-rdf-syntax-ns#type': u'<http://mmisw.org/ont/ioos/parameter/Parameter>',\n  u'Definition': u'\"Magnitude of wind velocity. Wind is motion of air relative to the surface of the earth.\"',\n  u'Term': u'\"wind_speed\"',\n  u'Units': u'\"m s-1\"',\n  u'core#exactMatch': u'<http://mmisw.org/ont/cf/parameter/wind_speed>',\n  u'rdf-schema#label': u'\"wind_speed\"'},\n {'definition': u'\"Magnitude of wind velocity. Wind is motion of air relative to the surface of the earth.\"',\n  'units': u'\"m s-1\"',\n  'units_type': 'example or common units',\n  'vocabulary': 'ioos/parameter'})"
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "get_term_ontmeta_jsonurl(ws_cf)",
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 5,
       "text": "({u'22-rdf-syntax-ns#type': u'<http://mmisw.org/ont/cf/parameter/Standard_Name>',\n  u'canonical_units': u'\"m s-1\"',\n  u'core#definition': u'\"Speed is the magnitude of velocity. Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.) The wind speed is the magnitude of the wind velocity.\"',\n  u'skos#exactMatch': u'<http://mmisw.org/ont/secoora/parameter/wind_speed>'},\n {'definition': u'\"Speed is the magnitude of velocity. Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.) The wind speed is the magnitude of the wind velocity.\"',\n  'units': u'\"m s-1\"',\n  'units_type': 'canonical units',\n  'vocabulary': 'cf/parameter'})"
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "# response for an invalid term url\nget_term_ontmeta_jsonurl('http://mmisw.org/ont/cf/parameter/uffda.json')",
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 6,
       "text": "(None, None)"
      }
     ],
     "prompt_number": 6
    }
   ],
   "metadata": {}
  }
 ]
}