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

Data model API

class mopidy.models.Ref(*args, **kwargs)

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

ALBUM = 'album'

Constant used for comparison with the type field.

ARTIST = 'artist'

Constant used for comparison with the type field.

DIRECTORY = 'directory'

Constant used for comparison with the type field.

PLAYLIST = 'playlist'

Constant used for comparison with the type field.

TRACK = 'track'

Constant used for comparison with the type field.

classmethod album(**kwargs)

Create a Ref with type ALBUM.

classmethod artist(**kwargs)

Create a Ref with type ARTIST.

classmethod directory(**kwargs)

Create a Ref with type DIRECTORY.

name

The object name. Read-only.

classmethod playlist(**kwargs)

Create a Ref with type PLAYLIST.

classmethod track(**kwargs)

Create a Ref with type TRACK.

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)

Parameters:

• uri (string) – track URI

• name (string) – track name

• artists (list of Artist) – track artists

• album (Album) – track album

• composers (list of Artist) – track composers

• performers (list of Artist) – track performers

• genre (string) – track genre

• track_no (integer or None if unknown) – track number in album

• disc_no (integer or None if unknown) – disc number in album

• date (string) – track release date (YYYY or YYYY-MM-DD)

• length (integer or None if there is no duration) – track length in milliseconds

• bitrate (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

album

The track Album. Read-only.

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)

Parameters:

• uri (string) – album URI

• name (string) – album name

• artists (list of Artist) – album artists

• num_tracks (integer or None if unknown) – number of tracks in album

• num_discs (integer or None if unknown) – number of discs in album

• date (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)

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)

Parameters:

• uri (string) – playlist URI

• name (string) – playlist name

• tracks (list of Track elements) – playlist’s tracks

• last_modified (int) – playlist’s modification time in milliseconds since Unix epoch

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)

Parameters:

• uri (string) – URI of the image

• width (int) – Optional width of image or None

• height (int) – Optional height of image or None

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)

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

Parameters:

• tlid (int) – tracklist ID

• track (Track) – the track

tlid

The tracklist ID. Read-only.

track

The track. Read-only.

class mopidy.models.SearchResult(*args, **kwargs)

Parameters:

• uri (string) – search result URI

• tracks (list of Track elements) – matching tracks

• artists (list of Artist elements) – matching artists

• albums (list of Album elements) – matching albums

albums

The albums matching the search query. Read-only.

artists

The artists matching the search query. Read-only.

tracks

The tracks matching the search query. Read-only.

uri

The search result URI. Read-only.

Data model helpers

class mopidy.models.ImmutableObject(*args, **kwargs)

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)

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)

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)

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)

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)

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)

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)

Specialized Field which is wired up for bytes and unicode.

Parameters:

default – default value for field

class mopidy.models.fields.Identifier(default=None)

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)

Field for storing URIs

Values will be interned, currently not validated.

Parameters:

default – default value for field

class mopidy.models.fields.Date(default=None)

Field for storing ISO 8601 dates as a string.

Supported formats are YYYY-MM-DD, YYYY-MM and YYYY, currently not validated.

Parameters:

default – default value for field

class mopidy.models.fields.Integer(default=None, min=None, max=None)

Field for storing integer numbers.

Parameters:

• default – default value for field

• min – field value must be larger or equal to this value when set

• max – field value must be smaller or equal to this value when set

class mopidy.models.fields.Collection(type, container=<class 'tuple'>)

Field for storing collections of a given type.

Parameters:

• type – all items stored in the collection must be of this type

• container – the type to store the items in