将按周每日数据的宽pandas数据帧转换为每日数据的长数据帧

import pandas as pd

# 创建按周每日数据的宽pandas数据帧
data = pd.DataFrame({
    'Week': ['Week 1', 'Week 2'],
    'Day 1': [10, 20],
    'Day 2': [30, 40],
    'Day 3': [50, 60]
})

# 使用melt()函数将数据转换为长格式
melted_data = pd.melt(data, id_vars=['Week'], value_vars=['Day 1', 'Day 2', 'Day 3'], var_name='Day', value_name='Value')

# 打印转换后的数据
print(melted_data)

     Week     Day  Value
0  Week 1  Day 1     10
1  Week 2  Day 1     20
2  Week 1  Day 2     30
3  Week 2  Day 2     40
4  Week 1  Day 3     50
5  Week 2  Day 3     60