问如何自定义seaborn的热图坐标并将任意数据放到热图中我想要的位置？

EN

import matplotlib.pyplot as plt
from matplotlib.colors import LogNorm
import seaborn as sns
import pandas as pd
import numpy as np

sns.set_style('white')
df = pd.DataFrame({'x': np.random.choice([*'KGORD'], 20),
                   'y': np.random.choice([*'CGLKU'], 20),
                   'extraction': 10000 ** np.random.uniform(0, 1, 20)})
df_dummy = pd.DataFrame({'x': [*'ABCDEFGHIJKLMNOPQRSTUVWXYZ'],
                         'y': [*'ABCDEFGHIJKLMNOPQRSTUVWXYZ'],
                         'extraction': np.nan})
keep='first').set_index(['x', 'y']).unstack()
df1 = pd.concat([df, df_dummy]) \
    .drop_duplicates(subset=['x', 'y'], keep='first') \
    .pivot(index='y', columns='x', values='extraction')
ax = sns.heatmap(data=df1, norm=LogNorm(), cmap='rocket_r')
ax.tick_params(labelrotation=0)
plt.tight_layout()
plt.show()