Fetching MultiIndex from groupby pandas

Question

What's an efficient way to extract second index after groupby against the maximum customer count per group.

Assume a dataframe df with various states and 10 officers (names Officer 1 to Officer 10 ) in every state. The column Current Status will always have value Customer :

    State List  Sales Officer   Current Status
0   UP          Officer 4       Customer
1   MH          Officer 5       Customer
2   AP          Officer 6       Customer
3   AN          Officer 2       Customer
4   GJ          Officer 3       Customer
.... so on

The expected output consists of sales officer with highest customer count in each state:

State List     Sales Officer      
AN             Officer 6          403
AP             Officer 1          266
               Officer 8          266
... and so on

So far I've performed the following:

df.groupby(['State List', 'Sales Officer'])['Current Status'].count()#.reset_index()

giving me the following:

State List  Sales Officer
AN          Officer 1        376
            Officer 10       401
            Officer 2        353
            Officer 3        373
            Officer 4        375
            Officer 5        382
            Officer 6        403
            Officer 7        400
            Officer 8        385
            Officer 9        378
AP          Officer 1        266
            Officer 10       228
            Officer 2        240
            Officer 3        248
            Officer 4        235
            Officer 5        229
            Officer 6        242
            Officer 7        238
            Officer 8        266
            Officer 9        243

Now, I'm stuck in fetching out the Sales Officer against each State List with maximum customer count. Any ideas!

Answer 1

Use boolean indexing with transform of max for return Series with same size like original:

s = df.groupby(['State List', 'Sales Officer'])['Current Status'].count()
df = s[s == s.groupby('State List').transform('max')]
print (df)
State List  Sales Officer
AN          Officer 6        403
AP          Officer 1        266
            Officer 8        266
Name: a, dtype: int64

Detail :

print (s.groupby('State List').transform('max'))
State List  Sales Officer
AN          Officer 1        403
            Officer 10       403
            Officer 2        403
            Officer 3        403
            Officer 4        403
            Officer 5        403
            Officer 6        403
            Officer 7        403
            Officer 8        403
            Officer 9        403
AP          Officer 1        266
            Officer 10       266
            Officer 2        266
            Officer 3        266
            Officer 4        266
            Officer 5        266
            Officer 6        266
            Officer 7        266
            Officer 8        266
            Officer 9        266
Name: a, dtype: int64