首先，您可以创建类似于this example的自定义离散色彩Map表。
其次，您可以创建一系列空图来保存图例的标签（假设您已经有了与每种颜色对应的标签列表）。
最后，bbox_to_anchor可用于将图例置于图外。有关此参数的更多详细信息，请参阅this excellent answer。
希望有帮助。

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import calmap
from matplotlib import colors

# Generating sample data
all_days = pd.date_range('01.01.2022', periods=700, freq='D')
days = np.random.choice(all_days, 500)
events = pd.Series(np.random.randn(len(days)), index=days)

# The colors and labels could be used from elsewhere as long as they are of the same size
cm_colors = ['blue', 'green', 'red']
cm_labels = ['Low', 'Medium', 'High']

cmap = colors.ListedColormap(cm_colors)

fig, ax = plt.subplots(figsize=(10, 3))
calmap.yearplot(events, cmap=cmap, vmin=events.min(), vmax=events.max(), linewidth=0.3, ax=ax)

for i in range(len(cm_colors)):
    ax.plot([],[],c=cmap.colors[i],label=cm_labels[i])

ax.legend(bbox_to_anchor=(1.04,0.5), loc='center left')
plt.title('Activity data across 2022')
fig.tight_layout()

plt.show()

结果是：

此外，calmap.yearplot源代码可以在这里找到。