beets/beetsplug/titlecase.py
henry b902352139
New Plugin: Titlecase (#6133)
This plugin aims to address the shortcomings of the %title function, as
brought up in issues #152, #3298 and an initial look to improvement with
#3411. It supplies a new string format command, `%titlecase` which
doesn't interfere with any prior expected behavior of the `%title`
format command.

It also adds the ability to apply titlecase logic to metadata fields
that a user selects, which is useful if you, like me, are looking for
stylistic consistency and the minor stylistic differences between
Musizbrainz, Discogs, Deezer etc, with title case are slightly
infuriating.

This will add an optional dependency of
[titlecase](https://pypi.org/project/titlecase/), which allows the
titlecase core logic to be externally maintained.

If there's not enough draw to have this as a core plugin, I can also
spin this into an independent one, but it seemed like a recurring theme
that the %title string format didn't really behave as expected, and I
wanted my metadata to match too.

- [x] Documentation. (If you've added a new command-line flag, for
example, find the appropriate page under `docs/` to describe it.)
- [x] Changelog. (Add an entry to `docs/changelog.rst` to the bottom of
one of the lists near the top of the document.)
- [x] Tests. - Not 100% coverage, but didn't see a lot of other plugins
with testing for import stages.
2025-11-23 10:34:05 -08:00

236 lines
8.8 KiB
Python

# This file is part of beets.
# Copyright 2025, Henry Oberholtzer
#
# 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.
"""Apply NYT manual of style title case rules, to text.
Title case logic is derived from the python-titlecase library.
Provides a template function and a tag modification function."""
import re
from functools import cached_property
from typing import TypedDict
from titlecase import titlecase
from beets import ui
from beets.autotag.hooks import AlbumInfo, Info
from beets.importer import ImportSession, ImportTask
from beets.library import Item
from beets.plugins import BeetsPlugin
__author__ = "henryoberholtzer@gmail.com"
__version__ = "1.0"
class PreservedText(TypedDict):
words: dict[str, str]
phrases: dict[str, re.Pattern[str]]
class TitlecasePlugin(BeetsPlugin):
def __init__(self) -> None:
super().__init__()
self.config.add(
{
"auto": True,
"preserve": [],
"fields": [],
"replace": [],
"seperators": [],
"force_lowercase": False,
"small_first_last": True,
"the_artist": True,
"after_choice": False,
}
)
"""
auto - Automatically apply titlecase to new import metadata.
preserve - Provide a list of strings with specific case requirements.
fields - Fields to apply titlecase to.
replace - List of pairs, first is the target, second is the replacement
seperators - Other characters to treat like periods.
force_lowercase - Lowercases the string before titlecasing.
small_first_last - If small characters should be cased at the start of strings.
the_artist - If the plugin infers the field to be an artist field
(e.g. the field contains "artist")
It will capitalize a lowercase The, helpful for the artist names
that start with 'The', like 'The Who' or 'The Talking Heads' when
they are not at the start of a string. Superceded by preserved phrases.
"""
# Register template function
self.template_funcs["titlecase"] = self.titlecase
# Register UI subcommands
self._command = ui.Subcommand(
"titlecase",
help="Apply titlecasing to metadata specified in config.",
)
if self.config["auto"].get(bool):
if self.config["after_choice"].get(bool):
self.import_stages = [self.imported]
else:
self.register_listener(
"trackinfo_received", self.received_info_handler
)
self.register_listener(
"albuminfo_received", self.received_info_handler
)
@cached_property
def force_lowercase(self) -> bool:
return self.config["force_lowercase"].get(bool)
@cached_property
def replace(self) -> list[tuple[str, str]]:
return self.config["replace"].as_pairs()
@cached_property
def the_artist(self) -> bool:
return self.config["the_artist"].get(bool)
@cached_property
def fields_to_process(self) -> set[str]:
fields = set(self.config["fields"].as_str_seq())
self._log.debug(f"fields: {', '.join(fields)}")
return fields
@cached_property
def preserve(self) -> PreservedText:
strings = self.config["preserve"].as_str_seq()
preserved: PreservedText = {"words": {}, "phrases": {}}
for s in strings:
if " " in s:
preserved["phrases"][s] = re.compile(
rf"\b{re.escape(s)}\b", re.IGNORECASE
)
else:
preserved["words"][s.upper()] = s
return preserved
@cached_property
def seperators(self) -> re.Pattern[str] | None:
if seperators := "".join(
dict.fromkeys(self.config["seperators"].as_str_seq())
):
return re.compile(rf"(.*?[{re.escape(seperators)}]+)(\s*)(?=.)")
return None
@cached_property
def small_first_last(self) -> bool:
return self.config["small_first_last"].get(bool)
@cached_property
def the_artist_regexp(self) -> re.Pattern[str]:
return re.compile(r"\bthe\b")
def titlecase_callback(self, word, **kwargs) -> str | None:
"""Callback function for words to preserve case of."""
if preserved_word := self.preserve["words"].get(word.upper(), ""):
return preserved_word
return None
def received_info_handler(self, info: Info):
"""Calls titlecase fields for AlbumInfo or TrackInfo
Processes the tracks field for AlbumInfo
"""
self.titlecase_fields(info)
if isinstance(info, AlbumInfo):
for track in info.tracks:
self.titlecase_fields(track)
def commands(self) -> list[ui.Subcommand]:
def func(lib, opts, args):
write = ui.should_write()
for item in lib.items(args):
self._log.info(f"titlecasing {item.title}:")
self.titlecase_fields(item)
item.store()
if write:
item.try_write()
self._command.func = func
return [self._command]
def titlecase_fields(self, item: Item | Info) -> None:
"""Applies titlecase to fields, except
those excluded by the default exclusions and the
set exclude lists.
"""
for field in self.fields_to_process:
init_field = getattr(item, field, "")
if init_field:
if isinstance(init_field, list) and isinstance(
init_field[0], str
):
cased_list: list[str] = [
self.titlecase(i, field) for i in init_field
]
if cased_list != init_field:
setattr(item, field, cased_list)
self._log.info(
f"{field}: {', '.join(init_field)} ->",
f"{', '.join(cased_list)}",
)
elif isinstance(init_field, str):
cased: str = self.titlecase(init_field, field)
if cased != init_field:
setattr(item, field, cased)
self._log.info(f"{field}: {init_field} -> {cased}")
else:
self._log.debug(f"{field}: no string present")
else:
self._log.debug(f"{field}: does not exist on {type(item)}")
def titlecase(self, text: str, field: str = "") -> str:
"""Titlecase the given text."""
# Check we should split this into two substrings.
if self.seperators:
if len(splits := self.seperators.findall(text)):
split_cased = "".join(
[self.titlecase(s[0], field) + s[1] for s in splits]
)
# Add on the remaining portion
return split_cased + self.titlecase(
text[len(split_cased) :], field
)
# Any necessary replacements go first, mainly punctuation.
titlecased = text.lower() if self.force_lowercase else text
for pair in self.replace:
target, replacement = pair
titlecased = titlecased.replace(target, replacement)
# General titlecase operation
titlecased = titlecase(
titlecased,
small_first_last=self.small_first_last,
callback=self.titlecase_callback,
)
# Apply "The Artist" feature
if self.the_artist and "artist" in field:
titlecased = self.the_artist_regexp.sub("The", titlecased)
# More complicated phrase replacements.
for phrase, regexp in self.preserve["phrases"].items():
titlecased = regexp.sub(phrase, titlecased)
return titlecased
def imported(self, session: ImportSession, task: ImportTask) -> None:
"""Import hook for titlecasing on import."""
for item in task.imported_items():
try:
self._log.debug(f"titlecasing {item.title}:")
self.titlecase_fields(item)
item.store()
except Exception as e:
self._log.debug(f"titlecasing exception {e}")