BUG: pandas.DataFrame.explode

[bigrogerio]

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Reproducible Example

import pandas as pd

df = pd.DataFrame({'A': [[0, 1, 2], 'foo', [], [3, 4]], 'B': 1, 'C': [['a', 'b', 'c'], np.nan, [], ['d', 'e']]})

df.explode('A')

# df is not changed.

Issue Description

When we explode a Dataframe using the method pandas.DataFrame.explode, it doesn`t apply the changes in the dataframe itself. To solve this problem a good way is to insert an "inplace" argument, that is not accepted in the moment.

Expected Behavior

df = pd.DataFrame({'A': [[0, 1, 2], 'foo', [], [3, 4]], 'B': 1, 'C': [['a', 'b', 'c'], np.nan, [], ['d', 'e']]})

df.explode('A')

# df is changed.

Installed Versions

In [2]: pd.show_versions()

INSTALLED VERSIONS

commit : e8093ba
python : 3.9.5.final.0
python-bits : 64
OS : Linux
OS-release : 5.4.0-1080-gcp
Version : #87~18.04.1-Ubuntu SMP Fri Jun 10 18:50:42 UTC 2022
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : C.UTF-8
LOCALE : en_US.UTF-8

pandas : 1.4.3
numpy : 1.23.1
pytz : 2021.3
dateutil : 2.8.2
setuptools : 56.0.0
pip : 22.1
Cython : None
pytest : 5.4.3
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : 1.1
pymysql : None
psycopg2 : None
jinja2 : 3.0.3
IPython : 8.0.1
pandas_datareader: None
bs4 : None
bottleneck : None
brotli : None
fastparquet : None
fsspec : 2022.02.0
gcsfs : 2022.02.0
markupsafe : 2.1.0
matplotlib : None
numba : None
numexpr : None
odfpy : None
openpyxl : 3.0.7
pandas_gbq : 0.17.5
pyarrow : 8.0.0
pyreadstat : None
pyxlsb : None
s3fs : None
scipy : 1.6.1
snappy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : 2.0.1
xlwt : 1.3.0
zstandard : None

[jreback]

-1 on adding inplace
this is an antipattern and going away

[mroeschke]

Agreed, this is not a bug as explode is not meant to operate inplace. We are removing inplace, so don't think it's worth adding. Closing

[bigrogerio]

Just a question: wouldn't be worth to make the method "explode" change de dataframe itself?

I raised this issue thinking that explode method should behave like the method "drop", for example.

[mroeschke]

wouldn't be worth to make the method "explode" change de dataframe itself

Can change via df = df.explode(...)