返回groupby pandas之后的所有行(即不是减少的行数，即组键的唯一值)

import pandas as pd

# 创建一个示例DataFrame
data = {'A': ['foo', 'bar', 'foo', 'bar', 'foo', 'bar', 'foo', 'foo'],
        'B': ['one', 'one', 'two', 'two', 'two', 'one', 'two', 'one'],
        'C': [1, 2, 3, 4, 5, 6, 7, 8]}
df = pd.DataFrame(data)

# 进行groupby操作
grouped = df.groupby(['A', 'B'])

# 返回groupby之后的所有行
for name, group in grouped:
    print(f"Group: {name}")
    print(group)

Group: ('bar', 'one')
     A    B  C
1  bar  one  2
Group: ('bar', 'two')
     A    B  C
3  bar  two  4
Group: ('foo', 'one')
     A    B  C
0  foo  one  1
5  foo  one  6
7  foo  one  8
Group: ('foo', 'two')
     A    B  C
2  foo  two  3
4  foo  two  5
6  foo  two  7