muon muon - 1 month ago 13
Python Question

pandas slicing multiindex dataframe

I want to slice a multi-index pandas dataframe

here is the code to obtain my test data:

import pandas as pd

testdf = {
'Name': {
0: 'H', 1: 'H', 2: 'H', 3: 'H', 4: 'H'}, 'Division': {
0: 'C', 1: 'C', 2: 'C', 3: 'C', 4: 'C'}, 'EmployeeId': {
0: 14, 1: 14, 2: 14, 3: 14, 4: 14}, 'Amt1': {
0: 124.39, 1: 186.78, 2: 127.94, 3: 258.35000000000002, 4: 284.77999999999997}, 'Amt2': {
0: 30.0, 1: 30.0, 2: 30.0, 3: 30.0, 4: 60.0}, 'Employer': {
0: 'Z', 1: 'Z', 2: 'Z', 3: 'Z', 4: 'Z'}, 'PersonId': {
0: 14, 1: 14, 2: 14, 3: 14, 4: 15}, 'Provider': {
0: 'A', 1: 'A', 2: 'A', 3: 'A', 4: 'B'}, 'Year': {
0: 2012, 1: 2012, 2: 2013, 3: 2013, 4: 2012}}
testdf = pd.DataFrame(testdf)
testdf
grouper_keys = [
'Employer',
'Year',
'Division',
'Name',
'EmployeeId',
'PersonId']

testdf2 = pd.pivot_table(data=testdf,
values='Amt1',
index=grouper_keys,
columns='Provider',
fill_value=None,
margins=False,
dropna=True,
aggfunc=('sum', 'count'),
)

print(testdf2)


gives:

enter image description here

Now I can get only
sum
for
A
or
B
using

testdf2.loc[:, slice(None, ('sum', 'A'))]


which gives

enter image description here

How can I get both
sum
and
count
for only
A
or
B

Answer

You can use:

idx = pd.IndexSlice
df = testdf2.loc[:, idx[['sum', 'count'], 'A']]
print (df)
                                                    sum count
Provider                                              A     A
Employer Year Division Name EmployeeId PersonId              
Z        2012 C        H    14         14        311.17   2.0
                                       15           NaN   NaN
         2013 C        H    14         14        386.29   2.0

Another solution:

df = testdf2.loc[:, (slice('sum','count'), ['A'])]
print (df)
                                                    sum count
Provider                                              A     A
Employer Year Division Name EmployeeId PersonId              
Z        2012 C        H    14         14        311.17   2.0
                                       15           NaN   NaN
         2013 C        H    14         14        386.29   2.0