sqlalchemy.ext.hybrid.hybrid

class documentation

class hybrid_property(interfaces.InspectionAttrInfo):

Known subclasses: sqlalchemy.ext.indexable.index_property

A decorator which allows definition of a Python descriptor with both instance-level and class-level behavior.

Method	`__init__`	Create a new `.hybrid_property`.
Method	`comparator`	Provide a modifying decorator that defines a custom comparator producing method.
Method	`deleter`	Provide a modifying decorator that defines a deletion method.
Method	`expression`	Provide a modifying decorator that defines a SQL-expression producing method.
Method	`getter`	Provide a modifying decorator that defines a getter method.
Method	`setter`	Provide a modifying decorator that defines a setter method.
Method	`update_expression`	Provide a modifying decorator that defines an UPDATE tuple producing method.
Method	`__delete__`	Undocumented
Method	`__get__`	Undocumented
Method	`__set__`	Undocumented
Method	`_copy`	Undocumented
Method	`_get_comparator`	Undocumented
Method	`_get_expr`	Undocumented
Class Variable	`is_attribute`	True if this object is a Python :term:`descriptor`.
Instance Variable	`custom_comparator`	Undocumented
Instance Variable	`expr`	Undocumented
Instance Variable	`fdel`	Undocumented
Instance Variable	`fget`	Undocumented
Instance Variable	`fset`	Undocumented
Instance Variable	`update_expr`	Undocumented
Property	`_expr_comparator`	Undocumented
Property	`overrides`	Prefix for a method that is overriding an existing attribute.

Inherited from InspectionAttrInfo:

Property info Info dictionary associated with the object, allowing user-defined data to be associated with this .InspectionAttr.

Inherited from InspectionAttr (via InspectionAttrInfo):

Class Variable	`__slots__`	Undocumented
Class Variable	`_is_internal_proxy`	True if this object is an internal proxy object.
Class Variable	`is_aliased_class`	True if this object is an instance of `.AliasedClass`.
Class Variable	`is_bundle`	True if this object is an instance of `.Bundle`.
Class Variable	`is_clause_element`	True if this object is an instance of `_expression.ClauseElement`.
Class Variable	`is_instance`	True if this object is an instance of `.InstanceState`.
Class Variable	`is_mapper`	True if this object is an instance of `_orm.Mapper`.
Class Variable	`is_property`	True if this object is an instance of `.MapperProperty`.
Class Variable	`is_selectable`	Return True if this object is an instance of `_expression.Selectable`.

def __init__(self, fget, fset=None, fdel=None, expr=None, custom_comparator=None, update_expr=None):

overridden in sqlalchemy.ext.indexable.index_property

Create a new .hybrid_property.

Usage is typically via decorator:

from sqlalchemy.ext.hybrid import hybrid_property

class SomeClass(object):
    @hybrid_property
    def value(self):
        return self._value

    @value.setter
    def value(self, value):
        self._value = value

def comparator(self, comparator):

Provide a modifying decorator that defines a custom comparator producing method.

The return value of the decorated method should be an instance of ~.hybrid.Comparator.

Note

The .hybrid_property.comparator decorator replaces the use of the .hybrid_property.expression decorator. They cannot be used together.

When a hybrid is invoked at the class level, the ~.hybrid.Comparator object given here is wrapped inside of a specialized .QueryableAttribute, which is the same kind of object used by the ORM to represent other mapped attributes. The reason for this is so that other class-level attributes such as docstrings and a reference to the hybrid itself may be maintained within the structure that's returned, without any modifications to the original comparator object passed in.

Note

When referring to a hybrid property from an owning class (e.g. SomeClass.some_hybrid), an instance of .QueryableAttribute is returned, representing the expression or comparator object as this hybrid object. However, that object itself has accessors called expression and comparator; so when attempting to override these decorators on a subclass, it may be necessary to qualify it using the .hybrid_property.overrides modifier first. See that modifier for details.

def deleter(self, fdel):

Provide a modifying decorator that defines a deletion method.

def expression(self, expr):

Provide a modifying decorator that defines a SQL-expression producing method.

When a hybrid is invoked at the class level, the SQL expression given here is wrapped inside of a specialized .QueryableAttribute, which is the same kind of object used by the ORM to represent other mapped attributes. The reason for this is so that other class-level attributes such as docstrings and a reference to the hybrid itself may be maintained within the structure that's returned, without any modifications to the original SQL expression passed in.

Note

When referring to a hybrid property from an owning class (e.g. SomeClass.some_hybrid), an instance of .QueryableAttribute is returned, representing the expression or comparator object as well as this hybrid object. However, that object itself has accessors called expression and comparator; so when attempting to override these decorators on a subclass, it may be necessary to qualify it using the .hybrid_property.overrides modifier first. See that modifier for details.

See Also

:ref:`hybrid_distinct_expression`

def getter(self, fget):

Provide a modifying decorator that defines a getter method.

New in version 1.2.

def setter(self, fset):

Provide a modifying decorator that defines a setter method.

def update_expression(self, meth):

Provide a modifying decorator that defines an UPDATE tuple producing method.

The method accepts a single value, which is the value to be rendered into the SET clause of an UPDATE statement. The method should then process this value into individual column expressions that fit into the ultimate SET clause, and return them as a sequence of 2-tuples. Each tuple contains a column expression as the key and a value to be rendered.

E.g.:

class Person(Base):
    # ...

    first_name = Column(String)
    last_name = Column(String)

    @hybrid_property
    def fullname(self):
        return first_name + " " + last_name

    @fullname.update_expression
    def fullname(cls, value):
        fname, lname = value.split(" ", 1)
        return [
            (cls.first_name, fname),
            (cls.last_name, lname)
        ]

New in version 1.2.

def __delete__(self, instance):

Undocumented

def __get__(self, instance, owner):

Undocumented

def __set__(self, instance, value):

Undocumented

def _copy(self, **kw):

Undocumented

def _get_comparator(self, comparator):

Undocumented

def _get_expr(self, expr):

Undocumented

is_attribute: bool =

overrides sqlalchemy.orm.base.InspectionAttr.is_attribute

True if this object is a Python :term:`descriptor`.

This can refer to one of many types. Usually a .QueryableAttribute which handles attributes events on behalf of a .MapperProperty. But can also be an extension type such as .AssociationProxy or .hybrid_property. The .InspectionAttr.extension_type will refer to a constant identifying the specific subtype.

sqlalchemy.ext.hybrid.hybrid_property

`sqlalchemy.ext.hybrid.hybrid_property`