dataset['CabinDeck'] = dataset.apply(lambda row:
                                     str(row['Cabin'])[0] if str(row['Cabin'])[0] != 'n'
                                     else row['Cabin'], axis=1)

sns.set(font_scale=1.5)
plt.style.use('seaborn-whitegrid')
g = sns.barplot('CabinDeck','Survived', data=dataset[dataset['CabinDeck'] != 'T'].sort_values('CabinDeck'))