向多列数据帧添加一种颜色和标记图例的Python图

import pandas as pd
import matplotlib.pyplot as plt

# 创建示例数据帧
data = {
    'x': [1, 2, 3, 4, 5],
    'y1': [2, 4, 6, 8, 10],
    'y2': [1, 3, 5, 7, 9],
    'y3': [3, 6, 9, 12, 15]
}
df = pd.DataFrame(data)

# 绘制图表
plt.plot(df['x'], df['y1'], color='red', marker='o', label='y1')
plt.plot(df['x'], df['y2'], color='blue', marker='s', label='y2')
plt.plot(df['x'], df['y3'], color='green', marker='^', label='y3')

# 添加图例
plt.legend()

# 显示图表
plt.show()