Python 3.10 is now available in preview.

google.appengine.ext.db.DateTimeProperty

The base class of all of our date/time properties.

Inherits From: Property, expected_type

We handle common operations, like converting between time tuples and datetime instances.

verbose_name Verbose name is always first parameter.
auto_now Date/time property is updated with the current time every time it is saved to the datastore. Useful for properties that want to track the modification time of an instance.
auto_now_add Date/time is set to the when its instance is created. Useful for properties that record the creation time of an entity.

Child Classes

class data_type

Methods

datastore_type

View source

Deprecated backwards-compatible accessor method for self.data_type.

default_value

View source

Default value for datetime.

Returns
value of now() as appropriate to the date-time instance if auto_now or auto_now_add is set, else user configured default value implementation.

empty

View source

Determine if value is empty in the context of this property.

For most kinds, this is equivalent to "not value", but for kinds like bool, the test is more subtle, so subclasses can override this method if necessary.

Args
value Value to validate against this Property.

Returns
True if this value is considered empty in the context of this Property type, otherwise False.

get_updated_value_for_datastore

View source

Get new value for property to send to datastore.

Returns
now() as appropriate to the date-time instance in the odd case where auto_now is set to True, else AUTO_UPDATE_UNCHANGED.

get_value_for_datastore

View source

Datastore representation of this property.

Looks for this property in the given model instance, and returns the proper datastore representation of the value that can be stored in a datastore entity. Most critically, it will fetch the datastore key value for reference properties.

Some properies (e.g. DateTimeProperty, UserProperty) optionally update their value on every put(). This call must return the current value for such properties (get_updated_value_for_datastore returns the new value).

Args
model_instance Instance to fetch datastore value from.

Returns
Datastore representation of the model value in a form that is appropriate for storing in the datastore.

make_value_from_datastore

View source

Native representation of this property.

Given a value retrieved from a datastore entity, return a value, possibly converted, to be stored on the model instance. Usually this returns the value unchanged, but a property class may override this when it uses a different datatype on the model instance than on the entity.

This API is not quite symmetric with get_value_for_datastore(), because the model instance on which to store the converted value may not exist yet -- we may be collecting values to be passed to a model constructor.

Args
value Value retrieved from the datastore entity.

Returns
The value converted for use as a model instance attribute.

make_value_from_datastore_index_value

View source

now

View source

Get now as a full datetime value.

Returns
'now' as a whole timestamp, including both time and date.

validate

View source

Validate datetime.

Returns
A valid value.

Raises
BadValueError if property is not instance of 'datetime'.

creation_counter 2