Curiosity: why are documented methods throwing AttributeError (is my ignorance showing?)

Ignition
14

short explanation for everyone asking:

  • list.get()
    • I wanted an expression structure binding parameter to support named query (including 'json' Return Format option and input parameters)
      • accomplished via runscript() and script transform on expression structure binding
      • enabled parameters to be passed as json string or java.util.hashMap (no dict in expressions)
      • scripting extensions module dataset to json arranges data differently
      • wanted to return a default like named query does
binding 
{
  "type": "expr-struct",
  "enabled": false,
  "config": {
    "struct": {
      "consoles": "runScript(\n\t\u0027_system.db.runNamedQuery\u0027,\n\t0,\n\t\u0027Consoles/getConsoles\u0027\n)",
      "userPrefs": "runScript(\n\t\u0027_system.db.runNamedQuery\u0027,\n\t0,\n\t\u0027Metadata/Get User Prefs\u0027, \n\tconcat(\"{\u0027Username\u0027:\", {session.props.auth.user.userName}, \"}\")\n)"
    },
    "waitOnAll": true
  },
  "transforms": [
    {
      "code": "\treturn {\n\t\t\u0027userPrefs\u0027:_system.dataset.pdsToJson(value.userPrefs).get(0,{}),\n\t\t\u0027consoles\u0027:_system.dataset.pdsToJson(value.consoles)\n\t}",
      "type": "script"
    }
  ]
}
_system 
'''
need to sublcass system.* instead of this hack
'''

class dataset:

	@staticmethod
	class pdsToJson(list):
		def __init__(self, pds):
			self.pds = [{colName: value for colName, value in zip(pds.columnNames, row)} for row in pds] if pds else []
			super(dataset.pdsToJson, self).__init__(self.pds)
	
		def get(self, index, default=None):
			if index < len(self.pds): return super(dataset.pdsToJson, self).__getitem__(index)
			return default

class db:

	@staticmethod
	def runNamedQuery(path, parameters = None, tx = None, getKey = None):
		import java.util.HashMap
		assert type(path) == str or unicode
		if type(parameters) ==  java.util.HashMap:
			return system.db.runNamedQuery(path, dict(parameters), tx, getKey)
		elif type(parameters) == str or unicode:
			return system.db.runNamedQuery(path, system.util.jsonDecode(parameters), tx, getKey)
		else: return system.db.runNamedQuery(path, parameters, tx, getKey)
  • PyJsonObjectAdapter.update()
    • was chaining script transforms (abandoned that per PTurmel's post on the matter)

basically I wanted one binding instead of multiple

critiques/alternatives welcome!
go easy on me