我有一个列表列表，all_genres其中每个子列表包含特定电视节目的类型，每个不同的子列表指的是不同的电视节目。我想绘制一个seaborn热图，但只有较低的三角形部分。这是我迄今为止尝试过的：
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
sns.set(rc={'figure.figsize':(16,9)})
all_genres = [['Drama', 'History'], ['Documentary'], ['Action', 'Drama', 'History'], ['Documentary'], ['Crime', 'Drama', 'Thriller'], ['Action', 'Adventure', 'Drama'], ['Crime', 'Drama', 'Thriller'], ['Documentary'], ['Documentary'], ['Documentary'], ['Animation', 'Adventure', 'Comedy'], ['Crime', 'Drama'], ['Documentary', 'History', 'War'], ['Animation', 'Action', 'Adventure'], ['Documentary'], ['Documentary', 'Music'], ['Crime', 'Drama', 'Mystery'], ['Documentary', 'History', 'War'], ['Fantasy', 'Horror', 'Mystery'], ['Documentary'], ['Drama'], ['Animation', 'Action', 'Adventure'], ['Adventure', 'Drama', 'Sci-Fi'], ['Documentary', 'History', 'War'], ['Biography', 'Drama', 'History'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Drama', 'Thriller'], …