Pure Python property implementation

class pproperty(object):
  def __init__(self, fget, fset=None, fdel=None, doc=None):
    self.fget = fget
    self.fset = fset
    self.fdel = fdel
    self.doc = doc or fget.__doc__

  def __get__(self, instance, owner):
    if instance:
      return self.fget(instance)
    return self

  def __set__(self, instance, value):
    if self.fset:
      self.fset(instance, value)
    else:
      raise AttributeError('can\'t set attribute')

  def __delete__(self, instance):
    if self.fdel:
      self.fdel(instance)
    else:
      raise AttributeError('can\'t delete attribute')

  def copy(self, **override_kwargs):
    curr_kwargs = {
        'fget': self.fget,
        'fset': self.fset,
        'fdel': self.fdel,
        'doc': self.doc,
    }
    curr_kwargs.update(override_kwargs)
    return self.__class__(**curr_kwargs)

  def getter(self, fget): return self.copy(fget=fget)
  def setter(self, fset): return self.copy(fset=fset)
  def deleter(self, fdel): return self.copy(fdel=fdel)