mopidy.models
--- Data models¶
These immutable data models are used for all data transfer within the Mopidy backends and between the backends and the MPD frontend. All fields are optional and immutable. In other words, they can only be set through the class constructor during instance creation. Additionally fields are type checked.
If you want to modify a model, use the
replace()
method. It accepts keyword
arguments for the parts of the model you want to change, and copies the rest of
the data from the model you call it on. Example:
>>> from mopidy.models import Track
>>> track1 = Track(name='Christmas Carol', length=171)
>>> track1
Track(artists=[], length=171, name='Christmas Carol')
>>> track2 = track1.replace(length=37)
>>> track2
Track(artists=[], length=37, name='Christmas Carol')
>>> track1
Track(artists=[], length=171, name='Christmas Carol')
Data model relations¶
![digraph model_relations {
Ref -> Album [ style="dotted", weight=1 ]
Ref -> Artist [ style="dotted", weight=1 ]
Ref -> Directory [ style="dotted", weight=1 ]
Ref -> Playlist [ style="dotted", weight=1 ]
Ref -> Track [ style="dotted", weight=1 ]
Playlist -> Track [ label="has 0..n", weight=2 ]
Track -> Album [ label="has 0..1", weight=10 ]
Track -> Artist [ label="has 0..n", weight=10 ]
Album -> Artist [ label="has 0..n", weight=10 ]
Image
SearchResult -> Artist [ label="has 0..n", weight=1 ]
SearchResult -> Album [ label="has 0..n", weight=1 ]
SearchResult -> Track [ label="has 0..n", weight=1 ]
TlTrack -> Track [ label="has 1", weight=20 ]
}](../_images/graphviz-5f0b5244ba4420904bd805c112bccb776250dc2c.png)
Data model API¶
-
class
mopidy.models.
Ref
(*args, **kwargs)[source]¶ Model to represent URI references with a human friendly name and type attached. This is intended for use a lightweight object "free" of metadata that can be passed around instead of using full blown models.
- Parameters
uri (string) -- object URI
name (string) -- object name
type (string) -- object type
-
name
¶ The object name. Read-only.
-
type
¶ The object type, e.g. "artist", "album", "track", "playlist", "directory". Read-only.
-
uri
¶ The object URI. Read-only.
-
class
mopidy.models.
Track
(*args, **kwargs)[source]¶ - Parameters
uri (string) -- track URI
name (string) -- track name
artists (list of
Artist
) -- track artistsalbum (
Album
) -- track albumcomposers (list of
Artist
) -- track composersperformers (list of
Artist
) -- track performersgenre (string) -- track genre
track_no (integer or
None
if unknown) -- track number in albumdisc_no (integer or
None
if unknown) -- disc number in albumdate (string) -- track release date (YYYY or YYYY-MM-DD)
length (integer or
None
if there is no duration) -- track length in millisecondsbitrate (integer) -- bitrate in kbit/s
comment (string) -- track comment
musicbrainz_id (string) -- MusicBrainz ID
last_modified (integer or
None
if unknown) -- Represents last modification time
-
artists
¶ A set of track artists. Read-only.
-
bitrate
¶ The track's bitrate in kbit/s. Read-only.
-
comment
¶ The track comment. Read-only.
-
composers
¶ A set of track composers. Read-only.
-
date
¶ The track release date. Read-only.
-
disc_no
¶ The disc number in the album. Read-only.
-
genre
¶ The track genre. Read-only.
-
last_modified
¶ Integer representing when the track was last modified. Exact meaning depends on source of track. For local files this is the modification time in milliseconds since Unix epoch. For other backends it could be an equivalent timestamp or simply a version counter.
-
length
¶ The track length in milliseconds. Read-only.
-
musicbrainz_id
¶ The MusicBrainz ID of the track. Read-only.
-
name
¶ The track name. Read-only.
-
performers
¶ A set of track performers`. Read-only.
-
track_no
¶ The track number in the album. Read-only.
-
uri
¶ The track URI. Read-only.
-
class
mopidy.models.
Album
(*args, **kwargs)[source]¶ - Parameters
uri (string) -- album URI
name (string) -- album name
artists (list of
Artist
) -- album artistsnum_tracks (integer or
None
if unknown) -- number of tracks in albumnum_discs (integer or
None
if unknown) -- number of discs in albumdate (string) -- album release date (YYYY or YYYY-MM-DD)
musicbrainz_id (string) -- MusicBrainz ID
-
artists
¶ A set of album artists. Read-only.
-
date
¶ The album release date. Read-only.
-
musicbrainz_id
¶ The MusicBrainz ID of the album. Read-only.
-
name
¶ The album name. Read-only.
-
num_discs
¶ The number of discs in the album. Read-only.
-
num_tracks
¶ The number of tracks in the album. Read-only.
-
uri
¶ The album URI. Read-only.
-
class
mopidy.models.
Artist
(*args, **kwargs)[source]¶ - Parameters
uri (string) -- artist URI
name (string) -- artist name
sortname (string) -- artist name for sorting
musicbrainz_id (string) -- MusicBrainz ID
-
musicbrainz_id
¶ The MusicBrainz ID of the artist. Read-only.
-
name
¶ The artist name. Read-only.
-
sortname
¶ Artist name for better sorting, e.g. with articles stripped
-
uri
¶ The artist URI. Read-only.
-
class
mopidy.models.
Playlist
(*args, **kwargs)[source]¶ - Parameters
-
last_modified
¶ The playlist modification time in milliseconds since Unix epoch. Read-only.
Integer, or
None
if unknown.
-
property
length
¶ The number of tracks in the playlist. Read-only.
-
name
¶ The playlist name. Read-only.
-
tracks
¶ The playlist's tracks. Read-only.
-
uri
¶ The playlist URI. Read-only.
-
class
mopidy.models.
Image
(*args, **kwargs)[source]¶ - Parameters
-
height
¶ Optional height of the image or
None
. Read-only.
-
uri
¶ The image URI. Read-only.
-
width
¶ Optional width of the image or
None
. Read-only.
-
class
mopidy.models.
TlTrack
(*args, **kwargs)[source]¶ A tracklist track. Wraps a regular track and it's tracklist ID.
The use of
TlTrack
allows the same track to appear multiple times in the tracklist.This class also accepts it's parameters as positional arguments. Both arguments must be provided, and they must appear in the order they are listed here.
This class also supports iteration, so your extract its values like this:
(tlid, track) = tl_track
-
tlid
¶ The tracklist ID. Read-only.
-
track
¶ The track. Read-only.
-
Data model helpers¶
-
class
mopidy.models.
ImmutableObject
(*args, **kwargs)[source]¶ Superclass for immutable objects whose fields can only be modified via the constructor.
This version of this class has been retained to avoid breaking any clients relying on it's behavior. Internally in Mopidy we now use
ValidatedImmutableObject
for type safety and it's much smaller memory footprint.- Parameters
kwargs (any) -- kwargs to set as fields on the object
-
replace
(**kwargs)[source]¶ Replace the fields in the model and return a new instance
Examples:
# Returns a track with a new name Track(name='foo').replace(name='bar') # Return an album with a new number of tracks Album(num_tracks=2).replace(num_tracks=5)
- Parameters
kwargs (any) -- kwargs to set as fields on the object
- Return type
instance of the model with replaced fields
-
class
mopidy.models.
ValidatedImmutableObject
(*args, **kwargs)[source]¶ Superclass for immutable objects whose fields can only be modified via the constructor. Fields should be
Field
instances to ensure type safety in our models.Note that since these models can not be changed, we heavily memoize them to save memory. So constructing a class with the same arguments twice will give you the same instance twice.
-
replace
(**kwargs)[source]¶ Replace the fields in the model and return a new instance
Examples:
# Returns a track with a new name Track(name='foo').replace(name='bar') # Return an album with a new number of tracks Album(num_tracks=2).replace(num_tracks=5)
Note that internally we memoize heavily to keep memory usage down given our overly repetitive data structures. So you might get an existing instance if it contains the same values.
- Parameters
kwargs (any) -- kwargs to set as fields on the object
- Return type
instance of the model with replaced fields
-
Data model (de)serialization¶
-
mopidy.models.
model_json_decoder
(dct)[source]¶ Automatically deserialize Mopidy models from JSON.
Usage:
>>> import json >>> json.loads( ... '{"a_track": {"__model__": "Track", "name": "name"}}', ... object_hook=model_json_decoder) {u'a_track': Track(artists=[], name=u'name')}
-
class
mopidy.models.
ModelJSONEncoder
(*, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, sort_keys=False, indent=None, separators=None, default=None)[source]¶ Automatically serialize Mopidy models to JSON.
Usage:
>>> import json >>> json.dumps({'a_track': Track(name='name')}, cls=ModelJSONEncoder) '{"a_track": {"__model__": "Track", "name": "name"}}'
Data model field types¶
-
class
mopidy.models.fields.
Field
(default=None, type=None, choices=None)[source]¶ Base field for use in
ValidatedImmutableObject
. These fields are responsible for type checking and other data sanitation in our models.For simplicity fields use the Python descriptor protocol to store the values in the instance dictionary. Also note that fields are mutable if the object they are attached to allow it.
Default values will be validated with the exception of
None
.- Parameters
default -- default value for field
type -- if set the field value must be of this type
choices -- if set the field value must be one of these
-
class
mopidy.models.fields.
String
(default=None)[source]¶ Specialized
Field
which is wired up for bytes and unicode.- Parameters
default -- default value for field
-
class
mopidy.models.fields.
Identifier
(default=None)[source]¶ Field
for storing values such as GUIDs or other identifiers.Values will be interned.
- Parameters
default -- default value for field
-
class
mopidy.models.fields.
URI
(default=None)[source]¶ Field
for storing URIsValues will be interned, currently not validated.
- Parameters
default -- default value for field
-
class
mopidy.models.fields.
Date
(default=None)[source]¶ Field
for storing ISO 8601 dates as a string.Supported formats are
YYYY-MM-DD
,YYYY-MM
andYYYY
, currently not validated.- Parameters
default -- default value for field