BUG: out-of-bounds pydatetime with errors='coerce' and non-ISO format coerces all elements to NaT

[MarcoGorelli]

Pandas version checks

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

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

• I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

# non-ISO
In [1]: to_datetime(['2020-01-01', dt.datetime(9999, 1, 1)], format='%Y-%d-%m', errors='coerce')
Out[1]: DatetimeIndex(['NaT', 'NaT'], dtype='datetime64[ns]', freq=None)

# ISO
In [2]: to_datetime(['2020-01-01', dt.datetime(9999, 1, 1)], format='%Y-%m-%d', errors='coerce')
Out[2]: DatetimeIndex(['2020-01-01', 'NaT'], dtype='datetime64[ns]', freq=None)

Issue Description

it shouldn't coerce all elements

Expected Behavior

Out[2]: DatetimeIndex(['2020-01-01', 'NaT'], dtype='datetime64[ns]', freq=None)

Installed Versions

INSTALLED VERSIONS

commit : 113bdb3
python : 3.8.15.final.0
python-bits : 64
OS : Linux
OS-release : 5.10.102.1-microsoft-standard-WSL2
Version : #1 SMP Wed Mar 2 00:30:59 UTC 2022
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : en_GB.UTF-8
LOCALE : en_GB.UTF-8

pandas : 2.0.0.dev0+918.g113bdb3769
numpy : 1.23.5
pytz : 2022.6
dateutil : 2.8.2
setuptools : 65.5.1
pip : 22.3.1
Cython : 0.29.32
pytest : 7.2.0
hypothesis : 6.61.0
sphinx : 4.5.0
blosc : None
feather : None
xlsxwriter : 3.0.3
lxml.etree : 4.9.1
html5lib : 1.1
pymysql : 1.0.2
psycopg2 : 2.9.3
jinja2 : 3.1.2
IPython : 8.7.0
pandas_datareader: None
bs4 : 4.11.1
bottleneck : 1.3.5
brotli :
fastparquet : 2022.12.0
fsspec : 2021.11.0
gcsfs : 2021.11.0
matplotlib : 3.6.2
numba : 0.56.4
numexpr : 2.8.3
odfpy : None
openpyxl : 3.0.10
pandas_gbq : None
pyarrow : 9.0.0
pyreadstat : 1.2.0
pyxlsb : 1.0.10
s3fs : 2021.11.0
scipy : 1.9.3
snappy :
sqlalchemy : 1.4.45
tables : 3.7.0
tabulate : 0.9.0
xarray : 2022.12.0
xlrd : 2.0.1
zstandard : 0.19.0
tzdata : None
qtpy : None
pyqt5 : None
None

[ShisuiUzumaki]

@MarcoGorelli Is it too complex? If not, I am interested. Could you guide me in resolving this bug?

[MarcoGorelli]

Gonna be completely honest - based on #50225, I'd suggest you become a bit more familiar with git / github first. I'd suggest the first 3 chapters of https://git-scm.com/book/en/v2

[ShisuiUzumaki]

Gonna be completely honest - based on #50225, I'd suggest you become a bit more familiar with git / github first. I'd suggest the first 3 chapters of https://git-scm.com/book/en/v2

Ok! Actually, I made a little mistake and that was I used git rebase main, not sure what I was thinking. The thing is most of these issues originated from that. Afterward, it just became a mess. Anyway, I will get work on my git skills Could you provide some resources to improve git skills beside the one you mentioned. Aside, from that, I would still like to try contributing, so if you think there are some easier issues that won't be too complicated, please let me know!