Selecting multiple rows of hierarchical DataFrame with Pandas MultiIndex

Question

I have a Pandas DataFrame with MultiIndex with 3 levels. Suppose I have the following data

df = pd.DataFrame({'ColB': {('A1', 'B1', 1): 'cb1',
  ('A1', 'B1', 2): 'cb2',
  ('A1', 'B2', 1): 'cb3',
  ('A1', 'B2', 2): 'cb4',
  ('A2', 'B1', 1): 'cb5',
  ('A2', 'B1', 2): 'cb6',
  ('A2', 'B2', 1): 'cb7',
  ('A2', 'B2', 2): 'cb8'},
 'colA': {('A1', 'B1', 1): 'ca1',
  ('A1', 'B1', 2): 'ca2',
  ('A1', 'B2', 1): 'ca3',
  ('A1', 'B2', 2): 'ca4',
  ('A2', 'B1', 1): 'ca5',
  ('A2', 'B1', 2): 'ca6',
  ('A2', 'B2', 1): 'ca7',
  ('A2', 'B2', 2): 'ca8'}})

        ColB colA
A1 B1 1  cb1  ca1
      2  cb2  ca2
   B2 1  cb3  ca3
      2  cb4  ca4
A2 B1 1  cb5  ca5
      2  cb6  ca6
   B2 1  cb7  ca7
      2  cb8  ca8

Now, I have a MultiIndex object that contains the index of the first two levels, like

MultiIndex([('A1', 'B2'),
            ('A2', 'B1')],
           )

I want to use that MultiIndex to select all the rows corresponding to that MultiIndex including all the index from level 3, such as,

        ColB colA
A1 B2 1  cb3  ca3
      2  cb4  ca4
A2 B1 1  cb5  ca5
      2  cb6  ca6

How can I do this? I've been searching for answer for hours but I still have no clue. Thank you.

Answer 1

Use Index.isin with remove 3rd level by MultiIndex.droplevel and filter by boolean indexing:

df = df[df.index.droplevel(2).isin(mux)]
print (df)
        ColB colA
A1 B2 1  cb3  ca3
      2  cb4  ca4
A2 B1 1  cb5  ca5
      2  cb6  ca6

It working correct for any index:

mux = pd.MultiIndex.from_tuples([('A1', 'B1'),('A2', 'B2')])

df = df[df.index.droplevel(2).isin(mux)]
print (df)
        ColB colA
A1 B1 1  cb1  ca1
      2  cb2  ca2
A2 B2 1  cb7  ca7
      2  cb8  ca8

Answer 2

I guess this is what you are looking for, you can try.

    df[('A1','B1')]

KR, Alex

Answer 3

Let's try Advanced indexing with hierarchical index

df.loc[('A1', 'B2'):('A2','B1')]

Out[56]: 
        ColB colA
A1 B2 1  cb3  ca3
      2  cb4  ca4
A2 B1 1  cb5  ca5
      2  cb6  ca6