Source Code for Package ndg.xacml

 1  """NDG XACML package  
 2   
 3  NERC DataGrid 
 4  """ 
 5  __author__ = "P J Kershaw" 
 6  __date__ = "16/03/10" 
 7  __copyright__ = "(C) 2010 Science and Technology Facilities Council" 
 8  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
 9  __license__ = "BSD - see LICENSE file in top-level directory" 
10  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
11  __revision__ = "$Id: __init__.py 8010 2012-01-30 16:24:06Z rwilkinson $" 
12 -class XacmlError(Exception): 
13      """Base class for XACML package exception types""" 
14   
15 -class Config(object): 
16      """Configuration options 
17      @type use_lxml: bool 
18      @cvar use_lxml: Controls whether lxml.etree should be imported instead of 
19      etree. lxml is required for XPath expressions with conditions. 
20      """ 
21      use_lxml = None 
22   
23 -def importElementTree(): 
24      """Imports ElementTree or the lxml ElementTree API depending on the 
25      Config.use_lxml value and whether the lxml package is found. 
26      @rtype: module 
27      @return: the element tree module that has been imported 
28      """ 
29      if Config.use_lxml is not None: 
30          if Config.use_lxml: 
31              from lxml import etree as ElementTree 
32          else: 
33              try: # python 2.5 
34                  from xml.etree import ElementTree 
35              except ImportError: 
36                  # if you've installed it yourself it comes this way 
37                  import ElementTree 
38      else: 
39          Config.use_lxml = False 
40          try: 
41              from lxml import etree as ElementTree 
42              Config.use_lxml = True 
43          except ImportError: 
44              try: # python 2.5 
45                  from xml.etree import ElementTree 
46              except ImportError: 
47                  # if you've installed it yourself it comes this way 
48                  import ElementTree 
49      return ElementTree 
50