BUG: guess_datetime_format fails to read 13/2019 in dateutil==2.8.1 #49144
Description
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
guess_datetime_format('13/2019')Issue Description
It returns
---------------------------------------------------------------------------
IllegalMonthError Traceback (most recent call last)
File ~/mambaforge/envs/pandas-dev/lib/python3.8/site-packages/dateutil/parser/_parser.py:655, in parser.parse(self, timestr, default, ignoretz, tzinfos, **kwargs)
654 try:
--> 655 ret = self._build_naive(res, default)
656 except ValueError as e:
File ~/mambaforge/envs/pandas-dev/lib/python3.8/site-packages/dateutil/parser/_parser.py:1238, in parser._build_naive(self, res, default)
1236 cday = default.day if res.day is None else res.day
-> 1238 if cday > monthrange(cyear, cmonth)[1]:
1239 repl['day'] = monthrange(cyear, cmonth)[1]
File ~/mambaforge/envs/pandas-dev/lib/python3.8/calendar.py:124, in monthrange(year, month)
123 if not 1 <= month <= 12:
--> 124 raise IllegalMonthError(month)
125 day1 = weekday(year, month, 1)
IllegalMonthError: bad month number 13; must be 1-12
During handling of the above exception, another exception occurred:
TypeError Traceback (most recent call last)
Cell In [1], line 1
----> 1 guess_datetime_format('13/2019')
File ~/pandas-dev/pandas/_libs/tslibs/parsing.pyx:991, in pandas._libs.tslibs.parsing.guess_datetime_format()
989
990 try:
--> 991 parsed_datetime = du_parse(dt_str, dayfirst=dayfirst)
992 except (ValueError, OverflowError):
993 # In case the datetime can't be parsed, its format cannot be guessed
File ~/mambaforge/envs/pandas-dev/lib/python3.8/site-packages/dateutil/parser/_parser.py:1374, in parse(timestr, parserinfo, **kwargs)
1372 return parser(parserinfo).parse(timestr, **kwargs)
1373 else:
-> 1374 return DEFAULTPARSER.parse(timestr, **kwargs)
File ~/mambaforge/envs/pandas-dev/lib/python3.8/site-packages/dateutil/parser/_parser.py:657, in parser.parse(self, timestr, default, ignoretz, tzinfos, **kwargs)
655 ret = self._build_naive(res, default)
656 except ValueError as e:
--> 657 six.raise_from(ParserError(e.args[0] + ": %s", timestr), e)
659 if not ignoretz:
660 ret = self._build_tzaware(ret, res, tzinfos)
TypeError: unsupported operand type(s) for +: 'int' and 'str'
Expected Behavior
It should just return None, as it does with dateutil version 2.8.2
Installed Versions
INSTALLED VERSIONS
commit : b07e31c
python : 3.8.13.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 : 1.6.0.dev0+353.gb07e31cfce
numpy : 1.23.3
pytz : 2022.2.1
dateutil : 2.8.1
setuptools : 59.8.0
pip : 22.2.2
Cython : 0.29.32
pytest : 7.1.3
hypothesis : 6.54.6
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 : 3.0.3
IPython : 8.5.0
pandas_datareader: 0.10.0
bs4 : 4.11.1
bottleneck : 1.3.5
brotli :
fastparquet : 0.8.3
fsspec : 2021.11.0
gcsfs : 2021.11.0
matplotlib : 3.6.0
numba : 0.56.2
numexpr : 2.8.3
odfpy : None
openpyxl : 3.0.10
pandas_gbq : 0.17.8
pyarrow : 9.0.0
pyreadstat : 1.1.9
pyxlsb : 1.0.9
s3fs : 2021.11.0
scipy : 1.9.1
snappy :
sqlalchemy : 1.4.41
tables : 3.7.0
tabulate : 0.8.10
xarray : 2022.9.0
xlrd : 2.0.1
xlwt : 1.3.0
zstandard : 0.18.0
tzdata : None
None