import pandas as pd
df = pd.read_csv('music_log_upd.csv')

genre_grouping = df.groupby('user_id')['genre_name']

def user_genres(group):
    for col in group:
        if len(col[1]) > 50:
            user = col[0]
            return user

search_id = user_genres(genre_grouping)

music_user = df[(df['user_id'] == search_id)&(df['total_play_seconds'] != 0)]