<p>不清楚你想要什么。在数据帧中,每个(天,级别0)键只有一行</p>
<p>我更改了您的数据帧:</p>
<pre><code>import pandas as pd
from io import StringIO
print(pd.__version__) # 1.0xx
s = '''
level_0 total_counts positive_day_chance
Monday 3M 1 0.8
Friday 3M 2 0.7
Monday 6M 3 0.6
Friday 6M 4 0.5
Monday 6M 5 0.4
Friday 3M 6 0.3
Friday 3M 7 0.2'''
df = pd.read_csv(StringIO(s), sep=r'\s+')
print('sort: False', '\n')
print(df.groupby([df.index, 'level_0'], sort = False).sum())
print('sort: True', '\n')
print(df.groupby([df.index, 'level_0']).sum())
</code></pre>
<hr/>
<pre><code>0.24.2
sort: False
total_counts positive_day_chance
level_0
Monday 3M 1 0.8
Friday 3M 15 1.2
Monday 6M 8 1.0
Friday 6M 4 0.5
sort: True
total_counts positive_day_chance
level_0
Friday 3M 15 1.2
6M 4 0.5
Monday 3M 1 0.8
6M 8 1.0
Process finished with exit code 0
</code></pre>
<p>使用<code>sort=False</code>时,不会对(日期,级别0)组键进行排序,而使用<code>sort=True</code>时,可以看到所有<code>Friday</code>行,然后是<code>Monday</code>行</p>
<p>另外,在我的示例中,您可以看到添加了列的值</p>