Python: matplotlib.pyplot ; lines = ax.plot(x, y) ; 如果y是2D的 pandas.DataFrame ; 如何一次加入所有欄標籤當作圖例(legend)的labels? labels= y.columns.tolist() ; ax.legend(lines, labels)

import matplotlib.pyplot as plt
import pandas as pd

# 示例数据
x = [1, 2, 3, 4, 5]
y = pd.DataFrame({
    'Data1': [2, 4, 6, 8, 10],
    'Data2': [3, 6, 9, 12, 15],
    'Data3': [1, 3, 5, 7, 9]
})

# 绘制图形
fig, ax = plt.subplots()
lines = ax.plot(x, y)
labels = y.columns.tolist()
ax.legend(lines, labels)
plt.show()