Throw ValueError for two digit year dates with dateutil.parser.parse

Question

While doing some data cleaning, I noticed that dateutil.parser.parse failed to reject a certain malformed date, thinking that the first number in it is a two digit year. Can this library be forced to treat two digit years as invalid?

Example:

from dateutil.parser import parse
parse('22-23 February')

outputs:

datetime.datetime(2022, 2, 23, 0, 0)

Answer 1

I managed to work around this by passing a custom dateutil.parser.parserinfo object via the parserinfo parameter to dateutil.parser.parse . Luckily, dateutil.parser.parserinfo has a convertyear method that can be overloaded in a derived class in order to perform extra validations on the year.

from dateutil.parser import parse, parserinfo

class NoTwoDigitYearParserInfo(parserinfo):
    def convertyear(self, year, century_specified=False):
        if year < 100 and not century_specified:
            raise ValueError('Two digit years are not supported.')
        return parserinfo.convertyear(self, year, century_specified)

parse('22-23 February', parserinfo = NoTwoDigitYearParserInfo())

outputs:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.5/site-packages/dateutil/parser.py", line 1162, in parse
    return parser(parserinfo).parse(timestr, **kwargs)
  File "/usr/local/lib/python3.5/site-packages/dateutil/parser.py", line 552, in parse
    res, skipped_tokens = self._parse(timestr, **kwargs)
  File "/usr/local/lib/python3.5/site-packages/dateutil/parser.py", line 1055, in _parse
    if not info.validate(res):
  File "/usr/local/lib/python3.5/site-packages/dateutil/parser.py", line 360, in validate
    res.year = self.convertyear(res.year, res.century_specified)
  File "<stdin>", line 4, in convertyear
ValueError: Two digit years are not supported.