Parent is a class - blue print not an instance of it,in OOPS to access attributes of an object it requires instance of the same,Here self/child is instance while Parent/Child are classes...

see the answer below, may clarify your doubts.

class Parent():    def __init__(self):        self.myvar = 1class Child(Parent):    def __init__(self):        Parent.__init__(self)        # here you can access myvar like below.        print self.myvarchild = Child()print child.myvar

Parent does not have an attribute called myvar. Only instances of parent have that attribute. From within a method of Child, you can access that attribute with self.myvar.

Alternative to using inheritance

The current answers are coming from an inheritance perspective, but this isn't always what you want -- sometimes you might want the child to be an entirely different type of object to the parent, but that still has access to the parent attributes.

For a business analogue, think of Excel Workbooks which have Worksheet children, which themselves have Range children, and so on.

Only Child

An alternative approach (and not the only one) is to pass the parent as an argument to the child to create a property that corresponds to the parent:

class Parent(object):    def __init__(self, parent_value):        self.parent_value = parent_value        self.child = Child(self)class Child(object):    def __init__(self, _parent):        self.parent = _parent        self.child_value = 0new_parent = Parent(1)print(new_parent.parent_value)        # prints 1new_child = new_parent.childprint(new_child.child_value)          # prints 0print(new_child.parent.parent_value)  # prints 1new_parent.parent_value = 100print(new_child.parent.parent_value)  # prints 100

Note that this instantiates the child at the same that that new_parent is instantiated. To access the parent's attributes, just go through the parent property.

Multiple Children

You could extend this so that you can create multiple instances of the Child class through the new_parent object. The code below is one simple way of doing this which replaces the child property with a children property and an add_child method.

class Parent(object):    def __init__(self, parent_value):        self.parent_value = parent_value        self.children = []    def add_child(self, child_value):        new_child = Child(child_value, _parent=self)        self.children.append(new_child)        return new_child  # allows add_child to assign a variableclass Child(object):    def __init__(self, child_value, _parent):        self.parent = _parent        self.child_value = child_valuenew_parent = Parent(1)# add 3 Child instances with child_values 2, 4, 8[new_parent.add_child(v) for v in [2, 4, 8]]# add another child that utilises the return statementextra_child = new_parent.add_child(16)for child in new_parent.children:    print(child.child_value)          # prints 2, 4, 8, 16    print(child.parent.parent_value)  # prints 1new_parent.parent_value = 32for child in new_parent.children:    print(child.parent.parent_value)  # prints 32# prove that extra_child is new_parent.children[3]extra_child.child_value = 64print(new_parent.children[3].child_value)  # prints 64