Source code for sima.lib.meta

# -*- coding: utf-8 -*-
# Copyright (c) 2013, 2014, 2015 kaliko <kaliko@azylum.org>
#
#  This file is part of sima
#
#  sima is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  sima is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with sima.  If not, see <http://www.gnu.org/licenses/>.
#
#
"""
Defines some object to handle audio file metadata
"""

try:
    from collections.abc import Set # python >= 3.3
except ImportError:
    from collections import Set # python 3.2
import logging
import re

UUID_RE = r'^[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12}$'
# The Track Object is collapsing multiple tags into a single string using this
# separator. It is used then to split back the string to tags list.
SEPARATOR = chr(0x1F)  # ASCII Unit Separator

[docs]def is_uuid4(uuid): """Controls MusicBrainz UUID4 format :param str uuid: String representing the UUID :returns: boolean """ regexp = re.compile(UUID_RE, re.IGNORECASE) if regexp.match(uuid): return True return False
[docs]class MetaException(Exception): """Generic Meta Exception""" pass
def mbidfilter(func): def wrapper(*args, **kwargs): cls = args[0] if not cls.use_mbid: kwargs.pop('mbid', None) kwargs.pop('musicbrainz_artistid', None) kwargs.pop('musicbrainz_albumartistid', None) func(*args, **kwargs) return wrapper def serialize(func): def wrapper(*args, **kwargs): ans = func(*args, **kwargs) if isinstance(ans, set): return {s.replace("'", r"\'") for s in ans} return ans.replace("'", r"\'") return wrapper
[docs]class Meta: """ A generic Class to handle tracks metadata such as artist, album, albumartist names and their associated MusicBrainz's ID. Using generic kwargs in constructor for convenience but the actual signature is: >>> Meta(name, mbid=None, **kwargs) :param str name: set name attribute :param str mbid: set MusicBrainz ID """ use_mbid = True """Class attribute to disable use of MusicBrainz IDs""" def __init__(self, **kwargs): """Meta(name=<str>[, mbid=UUID4])""" self.__name = None # TODO: should be immutable self.__mbid = None self.__aliases = set() self.log = logging.getLogger(__name__) if 'name' not in kwargs or not kwargs.get('name'): raise MetaException('Need a "name" argument (str type)') elif not isinstance(kwargs.get('name'), str): raise MetaException('"name" argument not a string') else: self.__name = kwargs.pop('name') if 'mbid' in kwargs and kwargs.get('mbid'): if is_uuid4(kwargs.get('mbid')): self.__mbid = kwargs.pop('mbid').lower() else: self.log.warning('Wrong mbid %s:%s', self.__name, kwargs.get('mbid')) # mbid immutable as hash rests on self.__dict__.update(**kwargs) def __repr__(self): fmt = '{0}(name={1.name!r}, mbid={1.mbid!r})' return fmt.format(self.__class__.__name__, self) def __str__(self): return self.__name.__str__() def __eq__(self, other): """ Perform mbid equality test """ #if hasattr(other, 'mbid'): # better isinstance? if isinstance(other, Meta) and self.mbid and other.mbid: return self.mbid == other.mbid elif isinstance(other, Meta): return bool(self.names & other.names) elif getattr(other, '__str__', None): # is other.__str__() in self.__name or self.__aliases return other.__str__() in self.names return False def __hash__(self): if self.mbid: return hash(self.mbid) return hash(self.__name)
[docs] def add_alias(self, other): """Add alternative name to `aliases` attibute. `other` can be a :class:`sima.lib.meta.Meta` object in which case aliases are merged. :param str other: Alias to add, could be any object with ``__str__`` method. """ if getattr(other, '__str__', None): if callable(other.__str__) and other.__str__() != self.name: self.__aliases |= {other.__str__()} elif isinstance(other, Meta): if other.name != self.name: self.__aliases |= other.__aliases else: raise MetaException('No __str__ method found in {!r}'.format(other))
@property def name(self): return self.__name @property @serialize def name_sz(self): return self.name @property def mbid(self): return self.__mbid @property def aliases(self): return self.__aliases @property @serialize def aliases_sz(self): return self.aliases @property def names(self): """aliases + name""" return self.__aliases | {self.__name,} @property @serialize def names_sz(self): return self.names
class Album(Meta): """Album object""" @mbidfilter def __init__(self, name=None, mbid=None, **kwargs): super().__init__(name=name, mbid=mbid, **kwargs) @property def album(self): return self.name
[docs]class Artist(Meta): """Artist object deriving from :class:`Meta`. :param str name: Artist name :param str mbid: Musicbrainz artist ID :param str artist: Overrides "name" argument :param str albumartist: Overrides "name" and "artist" argument :param str musicbrainz_artistid: Overrides "mbid" argument :param str musicbrainz_albumartistid: Overrides "musicbrainz_artistid" argument :Example: >>> trk = {'artist':'Art Name', >>> 'albumartist': 'Alb Art Name', # optional >>> 'musicbrainz_artistid': '<UUID4>', # optional >>> 'musicbrainz_albumartistid': '<UUID4>', # optional >>> } >>> artobj0 = Artist(**trk) >>> artobj1 = Artist(name='Tool') """ @mbidfilter def __init__(self, name=None, mbid=None, **kwargs): if kwargs.get('artist', False): name = kwargs.get('artist').split(SEPARATOR)[0] if kwargs.get('musicbrainz_artistid', False): mbid = kwargs.get('musicbrainz_artistid').split(SEPARATOR)[0] if (kwargs.get('albumartist', False) and kwargs.get('albumartist') != 'Various Artists'): name = kwargs.get('albumartist').split(SEPARATOR)[0] if (kwargs.get('musicbrainz_albumartistid', False) and kwargs.get('musicbrainz_albumartistid') != '89ad4ac3-39f7-470e-963a-56509c546377'): mbid = kwargs.get('musicbrainz_albumartistid').split(SEPARATOR)[0] super().__init__(name=name, mbid=mbid)
class MetaContainer(Set): def __init__(self, iterable): self.elements = lst = [] for value in iterable: if value not in lst: lst.append(value) else: for inlst in lst: if value == inlst: inlst.add_alias(value) def __iter__(self): return iter(self.elements) def __contains__(self, value): return value in self.elements def __len__(self): return len(self.elements) def __repr__(self): return repr(self.elements) # VIM MODLINE # vim: ai ts=4 sw=4 sts=4 expandtab