games_data['genre'] = games_data['genre'].fillna('unknown')
games_data['user_score'] = games_data['user_score'].replace({'tbd': np.nan})
games_data['user_score'] = games_data['user_score'].astype(float)

def fill(col):
    for platform in games_data.platform.unique():
        median_dict = games_data.query('platform == @platform').groupby('genre')[col].median()
        for genre in games_data.query('platform == @platform').genre.unique():
            games_data.loc[(games_data['platform'] == platform) & (games_data['genre'] == genre) & (np.isnan(games_data[col])), col] = median_dict.loc[genre]






fill('critic_score')
fill('user_score')