1. Google App Engine Property is the superclass for data model definitions. Query uses objects and methods to prepare queries.
Python SDK 1.2.2 REVISION 1.1 05.21.09
CONSTRUCTOR CONSTRUCTOR
class Property(verbose_name=None, name=None,
Datastore google.appengine.ext.db class Query(model_class)
indexed=True, default=None, choices=None
A scalable storage and query engine.
required=False, validator=None) INSTANCE METHODS
filter(property_operator, value) self
PACKAGE FUNCTIONS CLASS ATTRIBUTES
order(property) self
get(key) Model instance data_type
ancestor(model_instance|key) self
You can also pass multiple keys and it will return multiple Model instances. INSTANCE METHODS
get() model instance or None
put(model_instance) Key object default_value() value
fetch(limit, offset=0) list of model instances
You can also pass multiple model instances and it will return multiple keys. validate(value) value or exception
count(limit=None) integer
delete(model_instance|key) empty(value) bool
run_in_transaction(function, *args, **kwargs) TYPE AND PROPERTY CLASSES Key represents a unique key for a datastore entity.
run_in_transaction_custom_retries(retries, function, Property Class Value Type Sort Order CONSTRUCTOR
*args, **kwargs)
StringProperty str Unicode (str is treated as ASCII) class Key(encoded=None)
unicode
Model is the superclass for data model definitions. CLASS METHODS
ByteStringProperty db.ByteString byte order
CONSTRUCTOR Key.from_path(*args, **kwds)
BooleanProperty bool False True This example creates a key for an Address entity with the numeric ID 9876 whose par-
class Model(parent=None, key_name=None, **kwds)
ent is a User entity with the named key ‘Boris’:
IntegerProperty int Numeric
CLASS METHODS
long k = Key.from_path(‘User’, ‘Boris’, ‘Address’, 9876)
get(key) Key object
FloatProperty float Numeric
INSTANCE METHODS
get_by_id(id, parent=None) Model instance
DateTimeProperty datetime.datetime Chronological app() Application name (string)
You can also pass multiple ids and it will return multiple Model instances. DateProperty
kind() Kind (string)
get_by_key_name(key_name, parent=None) see above TimeProperty
ListProperty list If ascending, by least element; if id() Numeric ID (int)
You can also pass multiple ids and it will return multiple Model instances.
StringListProperty descending, by greatest element name() Entity name (string)
get_or_insert(key_name, **kwds) see above ReferenceProperty db.Key By path elements (kind, ID or name) id_or_name() Numeric ID(int) or name (string)
SelfReferenceProperty
all() Query object has_id_or_name() bool
UserProperty user.User By email address
gql(query_string, *args, **kwds) GQLQuery object parent() Key
Examples: BlobProperty db.Blob (not orderable)
s = Story.gql(“WHERE title = :1”, “The Little Prince”) TextProperty db.Text (not orderable)
GQL is a SQL-like language for retrieving entities.
s = Story.gql(“WHERE title = :title”, title=”The Little Prince”) SYNTAX
CategoryProperty db.Category Unicode
WHERE condition [AND condition ...]
kind() Kind
LinkProperty db.Link Unicode ORDER BY property [ASC | DESC] [,property [ASC | DESC]…]
properties() dict
LIMIT [offset,]count
EmailProperty db.Email Unicode
INSTANCE METHODS OFFSET offset
key() Key GeoPtProperty db.GeoPt By latitude, then longitude condition := property { | = | | = | = | != } value
put() Key IMProperty db.IM Unicode condition := property IN list
delete() condition := ANCESTOR IS entity or key
PhoneNumberProperty db.PhoneNumber Unicode
list := (value, …)
is_saved() bool
PostalAddressProperty db.PostalAddress Unicode Note that :NUMBER and :NAME are substitutions for positional and keyword argu-
parent() Model
ments, referrring to *args (starting at 1) and **kwds respectively. See
RatingProperty db.Rating Unicode
parent_key() Key Model.gql() for example usage. Key-only queries are supported using either
to_xml() XML SELECT __key__.

2. get_current_user() User invalid_email_reason(email_address, field) string
Memcache google.appengine.api.memcache is_current_user_admin() bool is_email_valid(email_address) Boolean
A distributed in-memory data cache that can be used in front of or in
EXCEPTIONS send_mail(sender, to, subject, body, **kw)
place of persistent storage.
Error, UserNotFound(), RedirectTooLongError() send_mail_to_admins(sender, subject, body, **kw)
FUNCTIONS EXCEPTIONS
set(key, value, time=0, min_compress_len=0) bool URL Fetch google.appengine.api.urlfetch Error, BadRequestError, InvalidEmailError,
The URLFetch API can retrieve data using HTTP and HTTPS URLs. InvalidAttachmentTypeError, MissingRecipientsError,
True means done while False means an error occured.
MisssingSenderError, MissingSubjectError,
Note that a Memcache key is an arbitrary string, not an instance of db.Key. MissingBodyError
FUNCTIONS
set_multi(mapping, time=0, key_prefix=’’, list MESSAGE FIELDS (**fields)
fetch(url, payload=None, method=GET, Response object
min_compress_len=0)
headers=(), allow_truncated=False, sender, to, cc, bcc, reply_to, subject, body, html,
get(key) value follow_redirects=True, deadline=5) attachments
get_multi(keys, key_prefix=’’) dict
RESPONSE OBJECTS
delete(key, seconds=0) error code content Images google.appengine.api.images
delete_multi(keys, seconds=0, key_prefix=’’) bool The body content of the response. Provides image manipulation using the Picassa Web infrastructure.
add(key, value, time=0, min_compress_len=0) bool
content_was_truncated
add_multi(mapping, time=0, key_prefix=’’, list Image represents image data to be transformed.
True if the allow_truncated parameter to fetch() was True and the
min_compress_len=0) response exceeded the maximum response size. In this case, the content attribute CONSTRUCTOR
replace(key, value, time=0, min_compress_len=0) bool contains the truncated response. class Image(image_data)
replace_multi(mapping, time=0, key_prefix=’’, list status_code PROPERTIES
min_compress_len=0)
The HTTP status code. width, height
incr(key, delta=1) int, long or None
headers INSTANCE METHODS
decr(key, delta=1) int, long or None
The HTTP response headers, as a mapping of names to values. resize(width=0, height=0)
flush_all() bool
EXCEPTION CLASSES crop(left_x, top_y, right_x, bottom_y)
get_stats() dict
Error, InvalidURLError, DownloadError, The four number arguments are multiplied by the image’s width and height to define
ResponseTooLargeError a bounding box that crops the image. The upper left point of the bounding box is at
User google.appengine.api.users (left_x*image_width, top_y*image_height) the lower right point is at
An App Engine application can redirect a user to a Google Accounts (right_x*image_width, bottom_y*image_height).
page to sign in register, or sign out. Mail google.appengine.api.urlfetch
rotate(clockwise_degrees)
Provides two ways to send an email message: the mail.send_mail()
horizontal_flip()
function and the EmailMessage class.
User represents a user with a Google account.
vertical_flip()
CONSTRUCTOR
EmailMessage represents an email message. im_feeling_lucky()
class User(email=None)
composite(inputs, width, height, color=0,
CONSTRUCTOR
INSTANCE METHODS output_encoding=images.PNG)
class EmailMessage(**fields)
email() string histogram(image_data) list
nickname() string
INSTANCE METHODS execute_transforms() Image Object
check_initialized()
user_id() string FUNCTIONS
initialize(**fields)
This can be the user id of an email address or the full email address if it differs from the They are the same as the instance methods, but they can be performed
application’s auth domain (gmail.com or the Google Apps domain for which the applica- is_initialized() bool directly on image_data. There is no need to queue them using execute_trans-
tion is registered). forms(). They include an additional parameter which is the expected
send()
output_encoding image type, which defaults to PNG.
FUNCTIONS FUNCTIONS
create_login_url(dest_url) string (URL) EXCEPTIONS
check_email_valid(email_address, field)
create_logout_url(dest_url) string (URL) Error, TransformationError, BadRequestError,
This raises an InvalidEmailError when the email_address is invalid.
NotImageError, BadImageError, LargeImageError