BUG: Series.explode ignores ignore_index parameter when series is not a nested type

[isVoid]

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

---

>>> s = pd.Series([1, 2], index=['a', 'b'])
>>> s.explode(ignore_index=True)
a    1
b    2
dtype: int64

Problem description

Even though exploding a non-nested array results in a no-op. ignore_index should still be considered to align with behavior of its dataframe sibling.

Expected Output

>>> s.explode(ignore_index=True)
0    1
1    2
dtype: int64

Output of pd.show_versions()

INSTALLED VERSIONS

commit : 3e89b4c
python : 3.7.10.final.0
python-bits : 64
OS : Linux
OS-release : 4.15.0-76-generic
Version : #86-Ubuntu SMP Fri Jan 17 17:24:28 UTC 2020
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : None
LOCALE : en_US.UTF-8

pandas : 1.2.0
numpy : 1.20.1
pytz : 2021.1
dateutil : 2.8.1
pip : 21.0.1
setuptools : 52.0.0.post20210125
Cython : 0.29.22
pytest : 6.2.2
hypothesis : 6.8.0
sphinx : 3.5.2
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 2.11.3
IPython : 7.21.0
pandas_datareader: None
bs4 : None
bottleneck : None
fsspec : 0.8.7
fastparquet : None
gcsfs : None
matplotlib : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : 1.0.1
pyxlsb : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
numba : 0.52.0

[phofl]

@dsaxton This issue was not closed. It looks like it was missed when the pr was merged?

[dsaxton]

Yeah, not sure why this wasn't closed automatically. Thanks @phofl.