old_contents: import os
  
  
  class env(object):
      def __init__(self, default=None):
          self.name = None
          self.default = default
  
      def __get__(self, obj, cls=None):
          if cls:
              return os.environ.get(self.name.upper(), self.default)
  
  
  class MetaConfig(type):
      '''Quickly tell the env attrs their names.'''
      def __new__(mcs, name, bases, attrs):
          for name, attr in attrs.items():
              if isinstance(attr, env):
                  env.name = name
          return super(MetaConfig, mcs).__new__(mcs, name, bases, attrs)
  
  
  class Conf(dict):
      '''
      Handy wrapper and placeholder of config values.
      '''
      __metaclass__ = MetaConfig
  
      def __getattr__(self, key):
          return os.environ[key]
  
new_contents: import os
  
  
  class env(object):
      def __init__(self, default=None):
          self.name = None
          self.default = default
  
      def __get__(self, obj, cls=None):
          if not obj:
              return self
          return os.environ.get(self.name.upper(), self.default)
  
  
  class MetaConfig(type):
      '''Quickly tell the env attrs their names.'''
      def __new__(mcs, name, bases, attrs):
          for name, attr in attrs.items():
              if isinstance(attr, env):
                  attr.name = name
          return super(MetaConfig, mcs).__new__(mcs, name, bases, attrs)
  
  
  class Conf(dict):
      '''
      Handy wrapper and placeholder of config values.
      '''
      __metaclass__ = MetaConfig
  
      def __getattr__(self, key):
          return os.environ[key]
  
subject: Fix detecting class access of descriptor. Set name on attr, not env class!