I've been working on a Python script which is an MP3 Tag editor. I need someone to go through my script and tell me whether I have written it correctly (following correct coding style) and where I can improve the code in term of readability, functionality, making it more Pythonic, etc.

Since it is little long and I've already posted it on Github's gist, please follow this link: https://gist.github.com/24Naman/d0c293d86e58d5f7a8fd8b536c5343f9

[Edit] The program is moved to a GitHub Repo, you can view it at https://github.com/24Naman/PyMTag


    Python: Created by Naman Jain on 12-01-2018
    File: music_file_tag_editor

    GUI Tag editor for MP3 file.
    It supports Tag editing using mutagen library, renaming the file based on its ID3 attributes,
    changing album art using local file system or using Internet search or removing it completely.

    It also supports changing cover art of all MP3 files with same album and album artist as the
    opened file.


# ## PyLint custom options: ## #
# pylint: disable=too-many-instance-attributes
# pylint: disable=c-extension-no-member
# pylint: disable=no-name-in-module

import os
import tempfile
from collections import OrderedDict
from contextlib import suppress, contextmanager
from functools import partial
from glob import glob
from typing import AnyStr, Tuple, Iterator

import shutil
from urllib.parse import urlunparse, quote, urlencode

import win32con
# noinspection PyProtectedMember
from kivy import Config
from kivy.app import App
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.checkbox import CheckBox
from kivy.uix.image import Image
from kivy.uix.label import Label
from kivy.uix.popup import Popup
from kivy.uix.spinner import Spinner
from kivy.uix.textinput import TextInput
from kivy.uix.widget import Widget

from mutagen import id3, File
from mutagen.easyid3 import EasyID3
# noinspection PyProtectedMember
from mutagen.id3 import APIC, ID3
from mutagen.mp3 import MP3

from win10toast import ToastNotifier

import win32api
import win32gui
from win32ui import CreateFileDialog
import winxpgui

class TagEditor(App, BoxLayout):
        Class for tag editor app

    # class attributes
    FILE_OPENED = False  # to store state of the opened file
    # File renaming options
    rename = {"no-rename": "Don't Rename", "album-title": "{Album} - {Title}",
              "album-artist-title": "{Album} - {Artist} - {Title}",
              "artist-album-title": "{Artist} - {Album} - {Title}",
              "title-album": "{Title} - {Album}"}

    class _Constants(OrderedDict):
            This class is for providing constants

        def __init__(self) -> None:
            self.title = 'Title'
            self.artist = 'Artist'
            self.album = 'Album'
            self.albumartist = 'Album Artists'
            self.date = 'Year'
            self.genre = 'Genre'

            self.window_title = "Musical - Music Tag Editor"

            self.default_tag_cover = os.path.join('extras', 'default_music.png')
            self.escape_button = os.path.join('extras', 'escape_label.png')

        def __getitem__(self, item) -> AnyStr:
            return self.__dict__[item]

        def __iter__(self) -> Iterator[str]:
            for name in ['title', 'artist', 'album', 'albumartist', 'date', 'genre']:
                yield name

    constants = _Constants()

    class _FileInfoLabel(Label):
            File Info Label

        def __init__(self, text: str, **kwargs) -> None:
            kwargs['text'] = f'[b][i][size=15][color=000000]{text}[/color][/i][/b]'
            kwargs['size_hint_x'] = 1
            kwargs['size_hint_y'] = 0.25
            kwargs['markup'] = True


        def pretty_text(self) -> str:
                Getter for text
            return self.text

        def pretty_text(self, value: str) -> None:
            self.text = f"[b][i][size=15][color=000000]{os.path.basename(value)}[/color][/font]" \

    def __init__(self, **kwargs):

        :param kwargs:
        :type kwargs:
        kwargs['orientation'] = 'vertical'

        self.title = TagEditor.constants.window_title

        # layouts
        self.main_layout = BoxLayout(orientation='horizontal')
        self.music_file_info_layout = BoxLayout(orientation='vertical', size_hint=(0.5, 1),
                                                pos_hint={'top': True, 'center_x': True})
        self.music_file_tag_layout = BoxLayout(orientation='vertical', size_hint=(0.5, 1))

        self.image_cover_art = Image(source=TagEditor.constants.default_tag_cover)
        self.label_file_name = self._FileInfoLabel('Open A File')
        self.button_album_art_change = Button(text="Options", size_hint=(0.25, 0.1),
                                              pos_hint={'center_x': 0.5},
                                              background_color=(255, 0, 0, 0.4),

        for widget in (self.image_cover_art, self.button_album_art_change, self.label_file_name,
                       Image(source=TagEditor.constants.escape_button, size_hint=(None, None),
                             size=(600, 200), pos_hint={'center_x': 0.725, 'bottom': True})):

        self.text_input_dict = {key: TextInput(hint_text_color=[26, 12, 232, 1],
                                               background_color=(0, 255, 255, 0.8))
                                for key in TagEditor.constants}

        self.checkbox_layout = BoxLayout(orientation='horizontal')
        self.checkbox_all_albums_art = CheckBox(active=True, color=[0, 0, 0, 1])

        def _label_select(_widget: Widget, _):
            self.checkbox_all_albums_art.active = not self.checkbox_all_albums_art.active

        label_all = self._FileInfoLabel(text="[ref=world]Apply this album art to all songs in the "
                                             "album[ref=world]", markup=True)

        for widget in (label_all, self.checkbox_all_albums_art):

        self.button_open = Button(text='Open', background_color=(255, 0, 0, 1),
        self.button_save = Button(text='Save', background_color=(255, 0, 0, 1),
        self.button_reset = Button(text='Reset', background_color=(255, 0, 0, 1),
        self.naming_opt = "no-rename"

        def _naming_option_selector(_, selected_text):
            binding function for the spinner, which assign the selected text to
            :param _:
            :type _:
            :param selected_text: the option selected by the user in the Spinner
            :type selected_text: str
            self.naming_opt = selected_text

        self.naming_option_spinner = Spinner(text=TagEditor.rename[self.naming_opt],
                                                     for key in TagEditor.rename])


        # Button's Layout
        self.layout_button = BoxLayout(orientation='horizontal')

        for widget in self.button_open, self.button_save, self.button_reset:

        # button bindings
        for button, binding in zip((self.button_open, self.button_save, self.button_reset,
                                   (self.file_open, self.save_file, self.reset_widgets,

        self.file_name, self.file_path, self.file_extension = str(), list(), str()
        self.to_delete = tempfile.TemporaryDirectory()

    def __repr__(self) -> str:
        return "TagEditor Class"

    def saving(file: File):
            calls save method on the object
        :param file: file to be saved
        :type file: File
        yield file

    def _return_popup(title: AnyStr, content: Widget, size: Tuple, size_hint=(None, None)) -> Popup:
            This method is for creating a unified Popup which will have a similar design
            throughout the application

        :param title: Title of the popup
        :type title: str
        :param content: content to be put in the popup
        :type content: Widget
        :param size: size of the Popup
        :type size: tuple
        :param size_hint: size hint of the Popup wrt to the parent
        :type size_hint: tuple; default=(None, None)
        :return: the generated Popup
        :rtype: Popup
        popup = Popup(title=title, content=content, size=size, size_hint=size_hint,
        return popup

    def build(self):
            building the App
        :return: the created window
        :rtype: TagEditor
        self.icon = TagEditor.constants.default_tag_cover

        # window background color
        Window.clearcolor = (255, 215, 0, 1)

        for key in self.text_input_dict:

        for widget in self.naming_option_spinner, self.checkbox_layout, self.layout_button:

        for widget in self.music_file_info_layout, self.music_file_tag_layout:


        return self

    def reset_widgets(self, _):
            Reset all field to original state
        self.label_file_name.pretty_text = 'Open A File'
        self.title = self.constants.window_title

        for key in self.text_input_dict:
            self.text_input_dict[key].text = ''
        if os.path.exists(os.path.join(os.getcwd(), TagEditor.constants.default_tag_cover)):
            self.image_cover_art.source = TagEditor.constants.default_tag_cover

        TagEditor.FILE_OPENED = False

        self.to_delete = tempfile.TemporaryDirectory()

    def file_open(self, _: Button) -> None:
            Opens a Windows file open dialog.
            It will use '.mp3' extension for file types

        :param _:
        :type _:
        # True, None for fileopen and False, File_Name for filesave dialog
        file_dialog = CreateFileDialog(True, ".mp3", None, 0, "MP3 Files (*.mp3)|*.mp3", None)

        # String, List, String
        self.file_name, self.file_path, self.file_extension = \
            file_dialog.GetFileName(), file_dialog.GetPathNames(), file_dialog.GetFileExt()

        # if no file is selected or cancel button is pressed
        if any([self.file_name == '', self.file_path == [], self.file_extension == '']):
            # if file open operation is cancelled, show a notification
            win_notification = ToastNotifier()
            win_notification.show_toast(self.title, "File open operation cancelled",

            audio_file, mp3_file = EasyID3(self.file_path[0]), MP3(self.file_path[0])

        except id3.ID3NoHeaderError:
            # adding tags if the file has none
            with self.saving(File(self.file_path[0], easy=True)) as file:

            audio_file, mp3_file = EasyID3(self.file_path[0]), MP3(self.file_path[0])

        if any(['APIC:Cover' in mp3_file, 'APIC:' in mp3_file]):
            with open(os.path.join(self.to_delete.name, 'image.jpeg'), 'wb') as img:
                img.write(mp3_file['APIC:' if 'APIC:' in mp3_file else 'APIC:Cover'].data)

            self.image_cover_art.source = os.path.join(self.to_delete.name, 'image.jpeg')

        self.title += f" -> {self.file_name}"
        self.label_file_name.pretty_text = self.file_name

        # filling the text field with the metadata of the song
        with suppress(KeyError):
            for key in self.text_input_dict:
                if not audio_file.get(key, self.text_input_dict[key].text) == "":
                    self.text_input_dict[key].text = \
                        audio_file.get(key, self.text_input_dict[key].text)[0]

        TagEditor.FILE_OPENED = True

    def save_file(self, _: Button) -> None:
        Save file and rename it according to the option selected by the user.

        :param _:
        :type _:

        if not TagEditor.FILE_OPENED:
            self._return_popup(title='No file opened', content=Label(text="Please open a file..."),
                               size=(500, 100)).open()

        file = None
        to_return = False
            file = MP3(self.file_path[0], ID3=ID3)
        except IndexError:
            self._return_popup(title="Error", content=Label(text='Please Open a file'),
                               size_hint=(None, None), size=(200, 200)).open()
            to_return = True

        with self.saving(file) as file:
            if to_return:
            with suppress(id3.error):

            if not self.image_cover_art.source == TagEditor.constants.default_tag_cover:
                with open(self.image_cover_art.source, 'rb') as alb_art:
                    file.tags.add(APIC(encoding=1, mime='image/png', type=3, desc=u'Cover',

                with suppress(KeyError):
                    if 'APIC:' in file:

                self.checkbox_all_albums_art.active = False

        with self.saving(EasyID3(self.file_path[0])) as music_file:
            # adding tags to the file
            for tag in self.text_input_dict:
                music_file[tag] = self.text_input_dict[tag].text

        self.file_name = self.file_path[0]

        # if the option is not "no-rename": "Don't Rename"
        if self.naming_opt != list(TagEditor.rename.keys())[0]:
            artist = music_file['artist'][0]
            album = music_file['album'][0]
            title = music_file['title'][0]

            # renaming the modified file with name according to the chosen option by the user
            self.file_name = self.naming_opt.format(Artist=artist, Album=album, Title=title)
            self.file_name = rf"{os.path.dirname(self.file_path[0])}\{self.file_name}.mp3"
            os.rename(self.file_path[0], self.file_name)
            self.file_path[0] = self.file_name

        self._return_popup(title='MP3 File Saved', content=Label(text=f'{self.file_name} Saved'),
                           size=(800, 200)).open()

        self.label_file_name.pretty_text = os.path.basename(self.file_name)

        TagEditor.FILE_OPENED = True

        if self.checkbox_all_albums_art.active:

        # resetting the widgets after saving the file

    def album_art_manager(self, _: Button) -> None:
            Function to grab the album art;
            it will offer three choice,
            Download from Internet or Pick from local filesystem or Remove the cover art
            :param _:
            :type _:

        if not TagEditor.FILE_OPENED:
            self._return_popup(title='No file opened', content=Label(text="Please open a file..."),
                               size=(500, 100)).open()

        # button for the popup
        button_local_picker = Button(text='Local Filesystem', background_color=(255, 0, 0, 1),
        button_google_search = Button(text='Search With Google', background_color=(255, 0, 0, 1),
        button_art_remove = Button(text='Remove Album Art', background_color=(255, 0, 0, 1),
        button_extract_art = Button(text='Extract The Album Art', background_color=(255, 0, 0, 1),

        art_button_layout = BoxLayout(orientation='vertical')
        art_picker = self._return_popup(title='Select Album Art', content=art_button_layout,
                                        size=(200, 200))

        # binding function to buttons in the popup
        for widget, callback in zip((button_google_search, button_local_picker, button_art_remove,
                                    (self.album_art_google, self.album_art_local,
                                     self.album_art_remove, self.album_art_extract)):
            widget.bind(on_press=partial(callback, art_picker=art_picker))


    def album_art_local(self, _: Button, art_picker: Popup, downloaded=False) -> None:
        Allows to selected the album art from the local file system.
        Opens the file dialog for selecting jpeg or png or jpg file

        It will open user's default Downloads folder in case the file is downloaded from the

        :param art_picker:
        :type art_picker: Popup
        :param _:
        :type _:
        :param downloaded: this parameter decides open dialog in last opened folder if 'False'
        otherwise opens in User's Download folder
        :type downloaded: Boolean
        file_types = "JPEG File (*.jpeg), jpg File (*.jpg) | *.jpg; *.jpeg; | PNG File (*.png) | " \
                     "*.png ||"

        # True for fileopen and False for filesave dialog
        # opening file dialog in Downloads folder if the image was searched online
        file_dialog = CreateFileDialog(True, os.path.join(os.getenv('USERPROFILE', 'Downloads'))
                                       if downloaded else None, None, 0, file_types, None)


        # assigning the mp3 cover art widget's source to selected image path
        if not file_dialog.GetPathNames()[0] == "":
            self.image_cover_art.source = file_dialog.GetPathNames()[0]

    def album_art_google(self, _: Button, art_picker: Popup) -> None:
        this method will open the browser (default Google Chrome) and search for the album art...

        :param art_picker:
        :type art_picker: Popup
        :param _:
        :type _: Button
        if self.text_input_dict["album"].text == "":
            self._return_popup(title='Empty Fields',
                               content=Label(text="Please fill Album and Artist field to perform "
                                                  "an auto search of album art"),
                               size=(500, 100)).open()

        # Google advance search query; tbm=isch -> image search; image size = 500*500
        search_url = urlunparse(('https', 'www.google.co.in', quote('search'), '',
                                 urlencode({'tbm': 'isch',
                                            'tbs': 'isz:ex,iszw:500,iszh:500',
                                            'as_q': f"{self.text_input_dict['albumartist'].text} "
                                                    f"{self.text_input_dict['album'].text} "
                                                    f"album art"}), ''))

        # open the default web browser to let the user download the image manually
        import webbrowser

        self.album_art_local(_, downloaded=True, art_picker=art_picker)

    def album_art_remove(self, _: Button, art_picker: Popup) -> None:
            Function for removing the album art from the MP3 File
        :param art_picker:
        :type art_picker: Popup
        :param _:
        :type _: Button

        file = MP3(self.file_path[0], ID3=ID3)
        self.image_cover_art.source = TagEditor.constants.default_tag_cover


        except KeyError:
            with suppress(KeyError):


    def album_art_extract(self, _: Button, art_picker: Popup) -> None:
            Extracting Album art and saving to disc
        :param art_picker:
        :type art_picker: Popup
        :param _:
        :type _: Button
        file_dialog = CreateFileDialog(False, None, "album_art.png", 0, "*.png| PNG File", None)

        file_path = file_dialog.GetPathNames()

        shutil.copy(self.image_cover_art.source, file_path[0])

    def album_art_all_songs(self, album: AnyStr, album_artist: AnyStr) -> None:
            Apply album art to all songs of the same album and artist
        :param album: the album name which album art has to be changed
        :type album: str
        :param album_artist: the album artist name which album art has to be changed
        :type album_artist: str
        for file_name in glob(f"{os.path.dirname(self.file_path[0])}/*.mp3"):
            music_file = EasyID3(file_name)

            if music_file['album'][0] == album and music_file['albumartist'][0] == album_artist:
                with self.saving(MP3(file_name)) as mp3_file:
                    with open(self.image_cover_art.source, 'rb') as alb_art:
                        mp3_file.tags.add(APIC(encoding=1, mime='image/png', type=3, desc=u'Cover',

    def on_start(self):
            this will be called when the app will start
            and it will do perform necessary modification

        # ## Window Custom Configuration ## #
        # making window non-resizable and borderless
        Config.set('graphics', 'resizable', False)
        Config.set('graphics', 'borderless', True)

        # window style values
        # reference ->
        # https://msdn.microsoft.com/en-us/library/windows/desktop/ms632600(v=vs.85).aspx
        gwl_style_dlgframe = 0x00400000
        gwl_style_sysmenu = 0x00080000
        gwl_style_thickframe = 0x00040000

        gwl_style_minimizebox = 0x00020000
        gwl_style_maximizebox = 0x00010000

        gwl_style_caption = gwl_style_dlgframe

        # Retrieves a handle to the top - level window whose class name and window name match the
        # specified strings.
        window_handler = win32gui.FindWindow(None, self.title)

        style = win32gui.GetWindowLong(window_handler, win32con.GWL_STYLE)
        style = style & (gwl_style_caption | gwl_style_thickframe |
                         gwl_style_minimizebox | gwl_style_maximizebox | gwl_style_sysmenu)
        win32gui.SetWindowLong(window_handler, win32con.GWL_STYLE, style)

        # making window transparent
        win32gui.SetWindowLong(window_handler, win32con.GWL_EXSTYLE,
                               win32gui.GetWindowLong(window_handler, win32con.GWL_EXSTYLE) |

        # Set the opacity and transparency color key of the windows
        winxpgui.SetLayeredWindowAttributes(window_handler, win32api.RGB(0, 0, 0), 220,

        # opening window in maximized mode
        win32gui.ShowWindow(window_handler, win32con.SW_MAXIMIZE)

    def on_stop(self):
            this will be called when the app will exit
            and it will delete any temporary directory created
        if self.to_delete is not None:

def main():
        Main Function

if __name__ == '__main__':
  • 1
    \$\begingroup\$ Unfortunately your question is off-topic as of now, as the code to be reviewed must be present in the question. Code behind links is considered non-reviewable. Please add the code you want reviewed in your question. \$\endgroup\$
    – Phrancis
    Apr 29 '18 at 20:40
  • 1
    \$\begingroup\$ It looks like the code is present now. \$\endgroup\$
    – chicks
    Apr 29 '18 at 22:17

This'll be a short review, because the code looks okay.

I think that the main problem with your code is that it's hard to figure out what part of the code is used to interact with the GUI vs what code is used to change the tags on the mp3 files.

You should try to separate your code in (at least) two classes :

  • The GUI
  • The MP3 tagger

This way, it's easier to maintain both parts, you could also end up creating a CLI tool that does the same thing as the GUI tool and you wouldn't need to rewrite a thing, you could just reuse the mp3 tagger class.

  • 1
    \$\begingroup\$ Thanks for your views. I will take your suggestion and hope that you will revisit the code after some time when I would have refactor the code. \$\endgroup\$
    – Naman Jain
    Aug 16 '19 at 16:27
  • \$\begingroup\$ @NamanJain Sure thing :) You can ping me in the comments of your next post if you'd like \$\endgroup\$
    – IEatBagels
    Aug 21 '19 at 14:37

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