sqlalchemy.orm.attributes.History

class documentation

class History(util.namedtuple('History', ['added', 'unchanged', 'deleted'])):

A 3-tuple of added, unchanged and deleted values, representing the changes which have occurred on an instrumented attribute.

The easiest way to get a .History object for a particular attribute on an object is to use the _sa.inspect function:

from sqlalchemy import inspect

hist = inspect(myobject).attrs.myattribute.history

Each tuple member is an iterable sequence:

added - the collection of items added to the attribute (the first tuple element).
unchanged - the collection of items that have not changed on the attribute (the second tuple element).
deleted - the collection of items that have been removed from the attribute (the third tuple element).

Class Method	`from_collection`	Undocumented
Class Method	`from_object_attribute`	Undocumented
Class Method	`from_scalar_attribute`	Undocumented
Method	`empty`	Return True if this `.History` has no changes and no existing, unchanged state.
Method	`has_changes`	Return True if this `.History` has changes.
Method	`non_added`	Return a collection of unchanged + deleted.
Method	`non_deleted`	Return a collection of added + unchanged.
Method	`sum`	Return a collection of added + unchanged + deleted.
Method	`__bool__`	Undocumented
Method	`as_state`	Undocumented

@classmethod
def from_collection(cls, attribute, state, current):

Undocumented

@classmethod
def from_object_attribute(cls, attribute, state, current, original=_NO_HISTORY):

Undocumented

@classmethod
def from_scalar_attribute(cls, attribute, state, current):

Undocumented

def empty(self):

Return True if this .History has no changes and no existing, unchanged state.

def has_changes(self):

Return True if this .History has changes.

def non_added(self):

Return a collection of unchanged + deleted.

def non_deleted(self):

Return a collection of added + unchanged.

def sum(self):

Return a collection of added + unchanged + deleted.

def __bool__(self):

Undocumented

def as_state(self):

Undocumented