object .__ delete __ (self, instance)
-> None
self - Reference to the instance.
instance - Instance of the descriptor owner class.
One of the methods for implementing the descriptor protocol . Allows you to define behavior when attempting to delete an owner-class attribute pointing to a descriptor.
class MyDescriptor (object):
"" "This is the class of the descriptor." ""
value = ’initial’
def __get __ (self, instance, owner):
# This often returns the value stored in the instance.
return self.value
def __delete __ (self, instance):
# Often deletes the value stored in instance.
self.value = ’erased’
class MyOwner (object):
"" "This is the class that owns the descriptors." ""
field1 = MyDescriptor ()
field2 = MyDescriptor ()
my_owner = MyOwner ()
my_owner .field1 # initial
del my_owner.field1
my_owner.field1 # erased 
