class_docstr: Initialize an instance of PomdpX reader class
  
  Parameters
  ----------
  path : file or str
      Path of the file containing PomdpX information.
  
  string : str
      String containing PomdpX information.
  
  Example
  -------
  reader = PomdpXReader('TestPomdpX.xml')
  
  Reference
  ---------
  http://bigbird.comp.nus.edu.sg/pmwiki/farm/appl/index.php?n=Main.PomdpXDocumentation
class_docstr_tok: ["Initialize","an","instance","of","PomdpX","reader","class","Parameters","--","--","--","--","--","path",":","file","or","str","Path","of","the","file","containing","PomdpX","information",".","string",":","str","String","containing","PomdpX","information",".","Example","--","--","--","-","reader","=","PomdpXReader","(","'TestPomdpX.xml","'",")","Reference","--","--","--","--","-","http",":","\/\/bigbird.comp.nus.edu.sg\/pmwiki\/farm\/appl\/index.php","?","n=Main.PomdpXDocumentation"]
code: def __init__(self, path=None, string=None):
      if path:
          self.network = etree.ElementTree(file=path).getroot()
      elif string:
          self.network = etree.fromstring(string)
      else:
          raise ValueError("Must specify either path or string")
  
imports: import xml.etree.ElementTree
  from collections import defaultdict
label_desc: Use image node_id 1 to create a new PomdpXReader object from inherited base classes: object with example: obj = PomdpXReader(path, string)