old_contents: #!/usr/bin/env python
  # filename: properties.py
  
  
  #
  # Copyright (c) 2015 Bryan Briney
  # License: The MIT license (http://opensource.org/licenses/MIT)
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy of this software
  # and associated documentation files (the "Software"), to deal in the Software without restriction,
  # including without limitation the rights to use, copy, modify, merge, publish, distribute,
  # sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in all copies or
  # substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
  # BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  # DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  #
  
  
  def lazy_property(fn):
      attr_name = '_lazy_' + fn.__name__
  
      @property
      def _lazy_property(self):
          if not hasattr(self, attr_name):
              setattr(self, attr_name, fn(self))
          return getattr(self, attr_name)
  
      return _lazy_property
  
new_contents: #!/usr/bin/env python
  # filename: properties.py
  
  
  #
  # Copyright (c) 2015 Bryan Briney
  # License: The MIT license (http://opensource.org/licenses/MIT)
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy of this software
  # and associated documentation files (the "Software"), to deal in the Software without restriction,
  # including without limitation the rights to use, copy, modify, merge, publish, distribute,
  # sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in all copies or
  # substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
  # BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  # DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  #
  
  
  def lazy_property(fn):
      attr_name = '_lazy_' + fn.__name__
  
      @property
      def _lazy_property(self):
          if not hasattr(self, attr_name):
              setattr(self, attr_name, fn(self))
          return getattr(self, attr_name)
  
      @_lazy_property.deleter
      def _lazyprop(self):
          if hasattr(self, attr_name):
              delattr(self, attr_name)
  
      @_lazy_property.setter
      def _lazyprop(self, value):
          setattr(self, attr_name, value)
  
      return _lazy_property
  
subject: add setting and deleting to lazy_property