code: def expand_system_vars(data):
      
      def _expanded(value):
          if isinstance(value, basestring):
              value = expandvars(value)
              value = expanduser(value)
              return scoped_format(value, system=system)
          elif isinstance(value, (list, tuple, set)):
              return [_expanded(x) for x in value]
          elif isinstance(value, dict):
              return dict((k, _expanded(v)) for k, v in value.iteritems())
          else:
              return value
      return _expanded(data)
docs: Expands any strings within `data` such as '{system.user}'.