rename_axis inplace=True

[scottboston]

Code Sample, a copy-pastable example if possible

import pandas as pd
import numpy as np

df = pd.DataFrame({'a':np.random.random(10),'b':np.random.random(10)})
df
df.rename_axis('numbers', inplace=True)
df

Problem description

df.rename_axis with the inplace=True should return None and make the named axis change the index name in the original object. However, up listing df again, no index name is present.

Expected Output

df.index.name should return 'numbers'

Output of pd.show_versions()

INSTALLED VERSIONS ------------------ commit: None python: 3.5.2.final.0 python-bits: 64 OS: Linux OS-release: 4.4.0-66-generic machine: x86_64 processor: x86_64 byteorder: little LC_ALL: None LANG: en_US.UTF-8

pandas: 0.18.1
nose: 1.3.7
pip: 9.0.1
setuptools: 27.2.0
Cython: 0.24.1
numpy: 1.11.1
scipy: 0.18.1
statsmodels: 0.6.1
xarray: None
IPython: 5.1.0
sphinx: 1.4.6
patsy: 0.4.1
dateutil: 2.5.3
pytz: 2016.6.1
blosc: None
bottleneck: 1.1.0
tables: 3.2.3.1
numexpr: 2.6.1
matplotlib: 1.5.3
openpyxl: 2.3.2
xlrd: 1.0.0
xlwt: 1.1.2
xlsxwriter: 0.9.3
lxml: 3.6.4
bs4: 4.5.1
html5lib: 0.999999999
httplib2: None
apiclient: None
sqlalchemy: 1.0.13
pymysql: None
psycopg2: None
jinja2: 2.8
boto: 2.42.0
pandas_datareader: 0.3.0.post

[TomAugspurger]

Not supporting inplace was a deliberate decision in #11980
If you want to change it inplace use df.index.name = name.

We could raise an exception if your renaming the axis label and inplace is true, rather than silently ignoring. Mind submitting a PR to fix that?

[jreback]

could support inplace as well, not a big deal (and we are already way down that road :<)

[gfyoung]

@jreback :

and we are already way down that road

Perhaps there will be a time when we can start deprecating inplace ? (Or rather, why do we want to go further down that road). 😄

[jreback]

Perhaps there will be a time when we can start deprecating inplace ? (Or rather, why do we want to go further down that road). 😄

pandas 2 will not support inplace

i suppose u can make an issue about deprecating it (at least DeprecationWarning) and see what reactions it brings

[gfyoung]

That's fair. I don't see why we shouldn't try deprecating.

xref #16529