all_progress = ['Unread', 'Reading', 'Read', 'Stopped']
langs = ['fr', 'en', 'de']

# Genres

all_genres = 'Tous les genres'
no_genre = 'Aucun genre'

def get_genres(books):
    genres = {all_genres}
    for data in books.values():
        for genre in data['genres']:
            genres.add(genre)
        if len(data['genres']) == 0:
            genres.add(no_genre)
    return list(genres)