如何获取按另一个字段分组的Pandas数据帧中的值之间的差异？

import pandas as pd

# 创建示例数据帧
data = {'Group': ['A', 'A', 'B', 'B', 'B', 'C', 'C'],
        'Value': [1, 2, 3, 4, 5, 6, 7]}
df = pd.DataFrame(data)

# 按Group字段分组并计算差异
df['Diff'] = df.groupby('Group')['Value'].diff()

print(df)

  Group  Value  Diff
0     A      1   NaN
1     A      2   1.0
2     B      3   NaN
3     B      4   1.0
4     B      5   1.0
5     C      6   NaN
6     C      7   1.0