environment/lib/python2.7/site-packages/IPython/utils/traitlets.py
def set_default_value(self, obj):
        """Set the default value on a per instance basis.

        This method is called by :meth:`instance_init` to create and
        validate the default value.  The creation and validation of
        default values must be delayed until the parent :class:`HasTraits`
        class has been instantiated.
        """
        # Check for a deferred initializer defined in the same class as the
        # trait declaration or above.
        mro = type(obj).mro()
        meth_name = '_%s_default' % self.name
        for cls in mro[:mro.index(self.this_class)+1]:
            if meth_name in cls.__dict__:
                break
        else:
            # We didn't find one. Do static initialization.
            dv = self.get_default_value()
            newdv = self._validate(obj, dv)
            obj._trait_values[self.name] = newdv
            return
        # Complete the dynamic initialization.
        obj._trait_dyn_inits[self.name] = cls.__dict__[meth_name]
def set_default_value(self, obj):
        """Set the default value on a per instance basis.

        This method is called by :meth:`instance_init` to create and
        validate the default value.  The creation and validation of
        default values must be delayed until the parent :class:`HasTraits`
        class has been instantiated.
        """
        # Check for a deferred initializer defined in the same class as the
        # trait declaration or above.
        mro = type(obj).mro()
        meth_name = '_%s_default' % self.name
        for cls in mro[:mro.index(self.this_class)+1]:
            if meth_name in cls.__dict__:
                break
        else:
            # We didn't find one. Do static initialization.
            dv = self.get_default_value()
            newdv = self._validate(obj, dv)
            obj._trait_values[self.name] = newdv
            return
        # Complete the dynamic initialization.
        obj._trait_dyn_inits[self.name] = cls.__dict__[meth_name]
Set the default value on a per instance basis.

        This method is called by :meth:`instance_init` to create and
        validate the default value.  The creation and validation of
        default values must be delayed until the parent :class:`HasTraits`
        class has been instantiated.