如何在我的绘图中为不同的散点设置相同的图例(标签)？

import matplotlib.pyplot as plt

# 创建绘图对象
fig, ax = plt.subplots()

# 准备数据集
data = [
    (1, 2, 'A'),
    (3, 4, 'B'),
    (5, 6, 'A'),
    (7, 8, 'C'),
    (9, 10, 'B')
]

# 创建空字典
scatter_dict = {}

# 遍历数据集
for x, y, label in data:
    # 判断字典中是否已存在该标签的散点图对象
    if label in scatter_dict:
        scatter = scatter_dict[label]
    else:
        # 创建新的散点图对象
        scatter = ax.scatter([], [], label=label)
        scatter_dict[label] = scatter
    
    # 添加当前散点到对应的散点图对象中
    scatter = ax.scatter(x, y, label=label)

# 遍历字典中的散点图对象
for scatter in scatter_dict.values():
    # 设置相同的图例（标签）
    ax.legend()

# 显示图形
plt.show()