ENH: Allow index names to be included in itertuples() result

[Dr-Irv]

Code Sample, a copy-pastable example if possible

In [1]: import pandas as pd

In [2]: df = pd.DataFrame({'x': [1, 2, 3, 4], 'y': [10, 20, 30, 40]},
            index=pd.MultiIndex.from_product([['a', 'b'], ['c', 'd']],
                                                names=['ab', 'cd']))
        df
Out[2]:
       x   y
ab cd
a  c   1  10
   d   2  20
b  c   3  30
   d   4  40

In [3]: for it in df.itertuples():
               print(it)

Pandas(Index=('a', 'c'), x=1, y=10)
Pandas(Index=('a', 'd'), x=2, y=20)
Pandas(Index=('b', 'c'), x=3, y=30)
Pandas(Index=('b', 'd'), x=4, y=40)

Problem description

When iterating through a DataFrame, the names of the Index are lost.

It would be really convenient if when a MultiIndex is used, the names of the MultiIndex were included in the result of itertuples().

Propose to add named argument to itertuples() called nameIndex with default value False to retain current behavior, and nameIndex=True causing output as shown below.

Expected Output

Pandas(Index=Index(ab='a', cd='c'), x=1, y=10)
Pandas(Index=Index(ab='a', cd='d'), x=2, y=20)
Pandas(Index=Index(ab='b', cd='c'), x=3, y=30)
Pandas(Index=Index(ab='b', cd='d'), x=4, y=40)

Output of pd.show_versions()

INSTALLED VERSIONS

commit : b57d523
python : 3.7.3.final.0
python-bits : 64
OS : Windows
OS-release : 10
machine : AMD64
processor : Intel64 Family 6 Model 60 Stepping 3, GenuineIntel
byteorder : little
LC_ALL : None
LANG : None
LOCALE : None.None

pandas : 0.25.0rc0+62.gb57d523b3
numpy : 1.16.4
pytz : 2019.1
dateutil : 2.8.0
pip : 19.1.1
setuptools : 41.0.1
Cython : 0.29.11
pytest : 5.0.0
hypothesis : 4.23.6
sphinx : 1.8.5
blosc : None
feather : None
xlsxwriter : 1.1.8
lxml.etree : 4.3.4
html5lib : 1.0.1
pymysql : None
psycopg2 : None
jinja2 : 2.10.1
IPython : 7.6.1
pandas_datareader: None
bs4 : 4.7.1
bottleneck : 1.2.1
fastparquet : 0.3.0
gcsfs : None
lxml.etree : 4.3.4
matplotlib : 3.1.0
numexpr : 2.6.9
odfpy : None
openpyxl : 2.6.2
pandas_gbq : None
pyarrow : 0.11.1
pytables : None
s3fs : 0.2.1
scipy : 1.2.1
sqlalchemy : 1.3.5
tables : 3.5.2
xarray : 0.12.1
xlrd : 1.2.0
xlwt : 1.3.0
xlsxwriter : 1.1.8

[akukuq]

I would like to add that even when using a normal index (i.e. not a MultiIndex) it is possible to assign that index a name (df.index.name = "some_name"). In such cases it would make sense to use the assigned name in the namedtuples yielded by itertuples.

Expected Output

>>> df = pd.DataFrame({"foo": [0,1,2]})
>>> df.index.name = "bar"
>>> next(df.itertuples())
Pandas(bar=0, foo=0) #Currently returns Pandas(Index=0, foo=0)

[konstantinmiller]

I would expect the same should work with iterrows():

import pandas as pd

df = pd.DataFrame(
    index=pd.MultiIndex(
        names=['ind1'],
        levels=[['a']],
        codes=[[0]]
    ),
    data={'C': [42]})

ind, row = next(df.iterrows())
row.C
ind.ind1

Since ind is not a named tuple, it throws an AttributeError: 'tuple' object has no attribute 'ind1'