From f35944f49c5afcd5e02a20c616802446dc534a43 Mon Sep 17 00:00:00 2001 From: Carl Suster Date: Sat, 6 Apr 2019 11:06:19 +1100 Subject: [PATCH] random: move implementation to beets.util.random --- beets/util/random.py | 110 +++++++++++++++++++++++++++++++++++++++++++ beetsplug/random.py | 92 +----------------------------------- 2 files changed, 111 insertions(+), 91 deletions(-) create mode 100644 beets/util/random.py diff --git a/beets/util/random.py b/beets/util/random.py new file mode 100644 index 000000000..2f385a246 --- /dev/null +++ b/beets/util/random.py @@ -0,0 +1,110 @@ +# -*- coding: utf-8 -*- +# This file is part of beets. +# Copyright 2016, Philippe Mongeau. +# +# Permission is hereby granted, free of charge, to any person obtaining +# a copy of this software and associated documentation files (the +# "Software"), to deal in the Software without restriction, including +# without limitation the rights to use, copy, modify, merge, publish, +# distribute, sublicense, and/or sell copies of the Software, and to +# permit persons to whom the Software is furnished to do so, subject to +# the following conditions: +# +# The above copyright notice and this permission notice shall be +# included in all copies or substantial portions of the Software. + +"""Get a random song or album from the library. +""" +from __future__ import division, absolute_import, print_function + +import random +from operator import attrgetter +from itertools import groupby + + +def _length(obj, album): + """Get the duration of an item or album. + """ + if album: + return sum(i.length for i in obj.items()) + else: + return obj.length + + +def _equal_chance_permutation(objs, field='albumartist'): + """Generate (lazily) a permutation of the objects where every group + with equal values for `field` have an equal chance of appearing in + any given position. + """ + # Group the objects by artist so we can sample from them. + key = attrgetter(field) + objs.sort(key=key) + objs_by_artists = {} + for artist, v in groupby(objs, key): + objs_by_artists[artist] = list(v) + + # While we still have artists with music to choose from, pick one + # randomly and pick a track from that artist. + while objs_by_artists: + # Choose an artist and an object for that artist, removing + # this choice from the pool. + artist = random.choice(list(objs_by_artists.keys())) + objs_from_artist = objs_by_artists[artist] + i = random.randint(0, len(objs_from_artist) - 1) + yield objs_from_artist.pop(i) + + # Remove the artist if we've used up all of its objects. + if not objs_from_artist: + del objs_by_artists[artist] + + +def _take(iter, num): + """Return a list containing the first `num` values in `iter` (or + fewer, if the iterable ends early). + """ + out = [] + for val in iter: + out.append(val) + num -= 1 + if num <= 0: + break + return out + + +def _take_time(iter, secs, album): + """Return a list containing the first values in `iter`, which should + be Item or Album objects, that add up to the given amount of time in + seconds. + """ + out = [] + total_time = 0.0 + for obj in iter: + length = _length(obj, album) + if total_time + length <= secs: + out.append(obj) + total_time += length + return out + + +def random_objs(objs, album, number=1, time=None, equal_chance=False): + """Get a random subset of the provided `objs`. + + If `number` is provided, produce that many matches. Otherwise, if + `time` is provided, instead select a list whose total time is close + to that number of minutes. If `equal_chance` is true, give each + artist an equal chance of being included so that artists with more + songs are not represented disproportionately. + """ + # Permute the objects either in a straightforward way or an + # artist-balanced way. + if equal_chance: + perm = _equal_chance_permutation(objs) + else: + perm = objs + random.shuffle(perm) # N.B. This shuffles the original list. + + # Select objects by time our count. + if time: + return _take_time(perm, time * 60, album) + else: + return _take(perm, number) diff --git a/beetsplug/random.py b/beetsplug/random.py index 65caaf908..567d5e069 100644 --- a/beetsplug/random.py +++ b/beetsplug/random.py @@ -19,97 +19,7 @@ from __future__ import division, absolute_import, print_function from beets.plugins import BeetsPlugin from beets.ui import Subcommand, decargs, print_ -import random -from operator import attrgetter -from itertools import groupby - - -def _length(obj, album): - """Get the duration of an item or album. - """ - if album: - return sum(i.length for i in obj.items()) - else: - return obj.length - - -def _equal_chance_permutation(objs, field='albumartist'): - """Generate (lazily) a permutation of the objects where every group - with equal values for `field` have an equal chance of appearing in - any given position. - """ - # Group the objects by artist so we can sample from them. - key = attrgetter(field) - objs.sort(key=key) - objs_by_artists = {} - for artist, v in groupby(objs, key): - objs_by_artists[artist] = list(v) - - # While we still have artists with music to choose from, pick one - # randomly and pick a track from that artist. - while objs_by_artists: - # Choose an artist and an object for that artist, removing - # this choice from the pool. - artist = random.choice(list(objs_by_artists.keys())) - objs_from_artist = objs_by_artists[artist] - i = random.randint(0, len(objs_from_artist) - 1) - yield objs_from_artist.pop(i) - - # Remove the artist if we've used up all of its objects. - if not objs_from_artist: - del objs_by_artists[artist] - - -def _take(iter, num): - """Return a list containing the first `num` values in `iter` (or - fewer, if the iterable ends early). - """ - out = [] - for val in iter: - out.append(val) - num -= 1 - if num <= 0: - break - return out - - -def _take_time(iter, secs, album): - """Return a list containing the first values in `iter`, which should - be Item or Album objects, that add up to the given amount of time in - seconds. - """ - out = [] - total_time = 0.0 - for obj in iter: - length = _length(obj, album) - if total_time + length <= secs: - out.append(obj) - total_time += length - return out - - -def random_objs(objs, album, number=1, time=None, equal_chance=False): - """Get a random subset of the provided `objs`. - - If `number` is provided, produce that many matches. Otherwise, if - `time` is provided, instead select a list whose total time is close - to that number of minutes. If `equal_chance` is true, give each - artist an equal chance of being included so that artists with more - songs are not represented disproportionately. - """ - # Permute the objects either in a straightforward way or an - # artist-balanced way. - if equal_chance: - perm = _equal_chance_permutation(objs) - else: - perm = objs - random.shuffle(perm) # N.B. This shuffles the original list. - - # Select objects by time our count. - if time: - return _take_time(perm, time * 60, album) - else: - return _take(perm, number) +from beets.util.random import random_objs def random_func(lib, opts, args):