dateparser.parse uses a default parser which tries to detect language every time it is called and is not the most efficient way while parsing dates from the same source.
DateDataParser <dateparser.date.DateDataParser> provides an alternate and efficient way to control language detection behavior.
The instance of DateDataParser <dateparser.date.DateDataParser> reduces the number of applicable languages, until only one or no language is left. It assumes the previously detected language for all the subsequent dates supplied.
This class wraps around the core dateparser functionality, and by default assumes that all of the dates fed to it are in the same language.
dateparser.date.DateDataParser
Warning
It fails to parse English dates in the example below, because Spanish was detected and stored with the ddp instance:
>>> ddp.get_date_data('11 August 2012') {'date_obj': None, 'period': 'day'}
dateparser.date.DateDataParser can also be initialized with known languages:
>>> ddp = DateDataParser(languages=['de', 'nl']) >>> ddp.get_date_data(u'vr jan 24, 2014 12:49') {'date_obj': datetime.datetime(2014, 1, 24, 12, 49), 'period': u'day'} >>> ddp.get_date_data(u'18.10.14 um 22:56 Uhr') {'date_obj': datetime.datetime(2014, 10, 18, 22, 56), 'period': u'day'}
dateparser's parsing behavior can be configured by supplying settings as a dictionary to settings argument in dateparser.parse or DateDataParser <dateparser.date.DateDataParser> constructor.
All supported settings with their usage examples are given below:
DATE_ORDER specifies the order in which date components year, month and day are expected while parsing ambiguous dates. It defaults to MDY which translates to month first, day second and year last order. Characters M, D or Y can be shuffled to meet required order. For example, DMY specifies day first, month second and year last order:
>>> parse('15-12-18 06:00') # assumes default order: MDY datetime.datetime(2018, 12, 15, 6, 0) # since 15 is not a valid value for Month, it is swapped with Day's >>> parse('15-12-18 06:00', settings={'DATE_ORDER': 'YMD'}) datetime.datetime(2015, 12, 18, 6, 0)
PREFER_LANGUAGE_DATE_ORDER defaults to True. Most languages have a default DATE_ORDER specified for them. For example, for French it is DMY:
>>> # parsing ambiguous date >>> parse('02-03-2016') # assumes english language, uses MDY date order datetime.datetime(2016, 2, 3, 0, 0) >>> parse('le 02-03-2016') # detects french, hence, uses DMY date order datetime.datetime(2016, 3, 2, 0, 0)
Note
There's no language level default DATE_ORDER associated with en language. That's why it assumes MDY which is `settings <dateparser.conf.settings> default. If the language has a default `DATE_ORDER associated, supplying custom date order will not be applied unless we set PREFER_LANGUAGE_DATE_ORDER to `False`:
>>> parse('le 02-03-2016', settings={'DATE_ORDER': 'MDY'}) datetime.datetime(2016, 3, 2, 0, 0) # MDY didn't apply
>>> parse('le 02-03-2016', settings={'DATE_ORDER': 'MDY', 'PREFER_LANGUAGE_DATE_ORDER': False}) datetime.datetime(2016, 2, 3, 0, 0) # MDY worked!
TIMEZONE defaults to local timezone. When specified, resultant datetime <datetime.datetime> is localized with the given timezone.
>>> parse('January 12, 2012 10:00 PM', settings={'TIMEZONE': 'US/Eastern'}) datetime.datetime(2012, 1, 12, 22, 0)
TO_TIMEZONE defaults to None. When specified, resultant datetime <datetime.datetime> converts according to the supplied timezone:
>>> settings = {'TIMEZONE': 'UTC', 'TO_TIMEZONE': 'US/Eastern'} >>> parse('January 12, 2012 10:00 PM', settings=settings) datetime.datetime(2012, 1, 12, 17, 0)
RETURN_AS_TIMEZONE_AWARE is a flag to toggle between timezone aware/naive dates:
>>> parse('30 mins ago', settings={'RETURN_AS_TIMEZONE_AWARE': True}) datetime.datetime(2017, 3, 13, 1, 43, 10, 243565, tzinfo=<DstTzInfo 'Asia/Karachi' PKT+5:00:00 STD>)
>>> parse('12 Feb 2015 10:56 PM EST', settings={'RETURN_AS_TIMEZONE_AWARE': False}) datetime.datetime(2015, 2, 12, 22, 56)
PREFER_DAY_OF_MONTH This option comes handy when the date string is missing the day part. It defaults to current and can have first and last denoting first and last day of months respectively as values:
>>> from dateparser import parse >>> parse(u'December 2015') # default behavior datetime.datetime(2015, 12, 16, 0, 0) >>> parse(u'December 2015', settings={'PREFER_DAY_OF_MONTH': 'last'}) datetime.datetime(2015, 12, 31, 0, 0) >>> parse(u'December 2015', settings={'PREFER_DAY_OF_MONTH': 'first'}) datetime.datetime(2015, 12, 1, 0, 0)
PREFER_DATES_FROM defaults to current_period and can have past and future as values.
If date string is missing some part, this option ensures consistent results depending on the past or future preference, for example, assuming current date is `June 16, 2015`:
>>> from dateparser import parse >>> parse(u'March') datetime.datetime(2015, 3, 16, 0, 0) >>> parse(u'March', settings={'PREFER_DATES_FROM': 'future'}) datetime.datetime(2016, 3, 16, 0, 0) >>> # parsing with preference set for 'past' >>> parse('August', settings={'PREFER_DATES_FROM': 'past'}) datetime.datetime(2015, 8, 15, 0, 0)
RELATIVE_BASE allows setting the base datetime to use for interpreting partial or relative date strings. Defaults to the current date and time.
For example, assuming current date is `June 16, 2015`:
>>> from dateparser import parse >>> parse(u'14:30') datetime.datetime(2015, 6, 16, 14, 30) >>> parse(u'14:30', settings={'RELATIVE_BASE': datetime.datetime(2020, 1, 1)}) datetime.datetime(2020, 1, 1, 14, 30) >>> parse(u'tomorrow', settings={'RELATIVE_BASE': datetime.datetime(2020, 1, 1)}) datetime.datetime(2020, 1, 2, 0, 0)
STRICT_PARSING defaults to False.
When set to True if missing any of day, month or year parts, it does not return any result altogether.:
>>> parse(u'March', settings={'STRICT_PARSING': True}) None
RETURN_TIME_AS_PERIOD returns time as period in date object, if time component was present in date string. Defaults to False.
>>> ddp = DateDataParser(settings={'RETURN_TIME_AS_PERIOD': True}) >>> ddp.get_date_data(u'vr jan 24, 2014 12:49') {'date_obj': datetime.datetime(2014, 1, 24, 12, 49), 'period': 'time', 'locale': 'nl'}
PARSERS is a list of names of parsers to try, allowing to customize which parsers are tried against the input date string, and in which order they are tried.
The following parsers exist:
'timestamp': If the input string starts with 10 digits, optionally followed by additional digits or a period (.), those first 10 digits are interpreted as Unix time.'relative-time': Parses dates and times expressed in relation to the current date and time (e.g. “1 day ago”, “in 2 weeks”).'custom-formats': Parses dates that match one of the date formats in the list of thedate_formatsparameter ofdateparser.parseorDateDataParser.get_date_data <dateparser.date.DateDataParser.get_date_data>.'absolute-time': Parses dates and times expressed in absolute form (e.g. “May 4th”, “1991-05-17”). It takes into account settings such asDATE_ORDERorPREFER_LOCALE_DATE_ORDER.'base-formats': Parses dates that match one of the following date formats:%B %d, %Y, %I:%M:%S %p %b %d, %Y at %I:%M %p %d %B %Y %H:%M:%S %A, %B %d, %Y %Y-%m-%dT%H:%M:%S.%fZ
dateparser.settings.default_parsers contains the default value of PARSERS (the list above, in that order) and can be used to write code that changes the parsers to try without skipping parsers that may be added to Dateparser in the future. For example, to ignore relative times:
>>> from dateparser.settings import default_parsers >>> parsers = [parser for parser in default_parsers if parser != 'relative-time'] >>> parse('today', settings={'PARSERS': parsers})
REQUIRE_PARTS This option ensures results are dates that have all specified parts. It defaults to [] and can include day, month and/or year.
For example, assuming current date is `June 16, 2019`:
>>> parse(u'2012') # default behavior datetime.datetime(2012, 6, 16, 0, 0) >>> parse(u'2012', settings={'REQUIRE_PARTS': ['month']}) None >>> parse(u'March 2012', settings={'REQUIRE_PARTS': ['day']}) None >>> parse(u'March 12, 2012', settings={'REQUIRE_PARTS': ['day']}) datetime.datetime(2012, 3, 12, 0, 0) >>> parse(u'March 12, 2012', settings={'REQUIRE_PARTS': ['day', 'month', 'year']}) datetime.datetime(2012, 3, 12, 0, 0)
SKIP_TOKENS is a list of tokens to discard while detecting language. Defaults to ['t'] which skips T in iso format datetime string .e.g. 2015-05-02T10:20:19+0000.:
>>> from dateparser.date import DateDataParser >>> DateDataParser(settings={'SKIP_TOKENS': ['de']}).get_date_data(u'27 Haziran 1981 de') # Turkish (at 27 June 1981) {'date_obj': datetime.datetime(1981, 6, 27, 0, 0), 'period': 'day'}