parser

This module offers a generic date/time string parser which is able to parse most known formats to represent a date and/or time.

This module attempts to be forgiving with regards to unlikely input formats, returning a datetime object even for dates which are ambiguous. If an element of a date/time stamp is omitted, the following rules are applied:

• If AM or PM is left unspecified, a 24-hour clock is assumed, however, an hour on a 12-hour clock (0 <= hour <= 12) must be specified if AM or PM is specified.

• If a time zone is omitted, a timezone-naive datetime is returned.

If any other elements are missing, they are taken from the datetime.datetime object passed to the parameter default. If this results in a day number exceeding the valid number of days per month, the value falls back to the end of the month.

Additional resources about date/time string formats can be found below:

• A summary of the international standard date and time notation

• W3C Date and Time Formats

• Time Formats (Planetary Rings Node)

• CPAN ParseDate module

• Java SimpleDateFormat Class

Functions

parser.parse(parserinfo=None, **kwargs)

Parse a string in one of the supported formats, using the parserinfo parameters.

Parameters:

• timestr – A string containing a date/time stamp.

• parserinfo – A parserinfo object containing parameters for the parser. If None, the default arguments to the parserinfo constructor are used.

The **kwargs parameter takes the following keyword arguments:

Parameters:

• default – The default datetime object, if this is a datetime object and not None, elements specified in timestr replace elements in the default object.

• ignoretz – If set True, time zones in parsed strings are ignored and a naive datetime object is returned.

• tzinfos –

  Additional time zone names / aliases which may be present in the string. This argument maps time zone names (and optionally offsets from those time zones) to time zones. This parameter can be a dictionary with timezone aliases mapping time zone names to time zones or a function taking two parameters (tzname and tzoffset) and returning a time zone.

  The timezones to which the names are mapped can be an integer offset from UTC in seconds or a tzinfo object.

   >>> from dateutil.parser import parse
   >>> from dateutil.tz import gettz
   >>> tzinfos = {"BRST": -7200, "CST": gettz("America/Chicago")}
   >>> parse("2012-01-19 17:21:00 BRST", tzinfos=tzinfos)
   datetime.datetime(2012, 1, 19, 17, 21, tzinfo=tzoffset(u'BRST', -7200))
   >>> parse("2012-01-19 17:21:00 CST", tzinfos=tzinfos)
   datetime.datetime(2012, 1, 19, 17, 21,
                     tzinfo=tzfile('/usr/share/zoneinfo/America/Chicago'))
  

  This parameter is ignored if ignoretz is set.

• dayfirst – Whether to interpret the first value in an ambiguous 3-integer date (e.g. 01/05/09) as the day (True) or month (False). If yearfirst is set to True, this distinguishes between YDM and YMD. If set to None, this value is retrieved from the current parserinfo object (which itself defaults to False).

• yearfirst – Whether to interpret the first value in an ambiguous 3-integer date (e.g. 01/05/09) as the year. If True, the first number is taken to be the year, otherwise the last number is taken to be the year. If this is set to None, the value is retrieved from the current parserinfo object (which itself defaults to False).

• fuzzy – Whether to allow fuzzy parsing, allowing for string like “Today is January 1, 2047 at 8:21:00AM”.

• fuzzy_with_tokens –

  If True, fuzzy is automatically set to True, and the parser will return a tuple where the first element is the parsed datetime.datetime datetimestamp and the second element is a tuple containing the portions of the string which were ignored:

  >>> from dateutil.parser import parse
  >>> parse("Today is January 1, 2047 at 8:21:00AM", fuzzy_with_tokens=True)
  (datetime.datetime(2047, 1, 1, 8, 21), (u'Today is ', u' ', u'at '))
  

Returns:

Returns a datetime.datetime object or, if the fuzzy_with_tokens option is True, returns a tuple, the first element being a datetime.datetime object, the second a tuple containing the fuzzy tokens.

Raises:

• ParserError – Raised for invalid or unknown string formats, if the provided tzinfo is not in a valid format, or if an invalid date would be created.

• OverflowError – Raised if the parsed date exceeds the largest valid C integer on your system.

parser.isoparse(dt_str)

Parse an ISO-8601 datetime string into a datetime.datetime.

An ISO-8601 datetime string consists of a date portion, followed optionally by a time portion - the date and time portions are separated by a single character separator, which is T in the official standard. Incomplete date formats (such as YYYY-MM) may not be combined with a time portion.

Supported date formats are:

Common:

• YYYY

• YYYY-MM

• YYYY-MM-DD or YYYYMMDD

Uncommon:

• YYYY-Www or YYYYWww - ISO week (day defaults to 0)

• YYYY-Www-D or YYYYWwwD - ISO week and day

The ISO week and day numbering follows the same logic as datetime.date.isocalendar().

Supported time formats are:

• hh

• hh:mm or hhmm

• hh:mm:ss or hhmmss

• hh:mm:ss.ssssss (Up to 6 sub-second digits)

Midnight is a special case for hh, as the standard supports both 00:00 and 24:00 as a representation. The decimal separator can be either a dot or a comma.

Caution

Support for fractional components other than seconds is part of the ISO-8601 standard, but is not currently implemented in this parser.

Supported time zone offset formats are:

• Z (UTC)

• ±HH:MM

• ±HHMM

• ±HH

Offsets will be represented as dateutil.tz.tzoffset objects, with the exception of UTC, which will be represented as dateutil.tz.tzutc. Time zone offsets equivalent to UTC (such as +00:00) will also be represented as dateutil.tz.tzutc.

Parameters:

dt_str – A string or stream containing only an ISO-8601 datetime string

Returns:

Returns a datetime.datetime representing the string. Unspecified components default to their lowest value.

Warning

As of version 2.7.0, the strictness of the parser should not be considered a stable part of the contract. Any valid ISO-8601 string that parses correctly with the default settings will continue to parse correctly in future versions, but invalid strings that currently fail (e.g. 2017-01-01T00:00+00:00:00) are not guaranteed to continue failing in future versions if they encode a valid date.

New in version 2.7.0.

Classes

class dateutil.parser.parserinfo(dayfirst=False, yearfirst=False)

Class which handles what inputs are accepted. Subclass this to customize the language and acceptable values for each parameter.

Parameters:

• dayfirst – Whether to interpret the first value in an ambiguous 3-integer date (e.g. 01/05/09) as the day (True) or month (False). If yearfirst is set to True, this distinguishes between YDM and YMD. Default is False.

• yearfirst – Whether to interpret the first value in an ambiguous 3-integer date (e.g. 01/05/09) as the year. If True, the first number is taken to be the year, otherwise the last number is taken to be the year. Default is False.

AMPM = [('am', 'a'), ('pm', 'p')]

HMS = [('h', 'hour', 'hours'), ('m', 'minute', 'minutes'), ('s', 'second', 'seconds')]

JUMP = [' ', '.', ',', ';', '-', '/', "'", 'at', 'on', 'and', 'ad', 'm', 't', 'of', 'st', 'nd', 'rd', 'th']

MONTHS = [('Jan', 'January'), ('Feb', 'February'), ('Mar', 'March'), ('Apr', 'April'), ('May', 'May'), ('Jun', 'June'), ('Jul', 'July'), ('Aug', 'August'), ('Sep', 'Sept', 'September'), ('Oct', 'October'), ('Nov', 'November'), ('Dec', 'December')]

PERTAIN = ['of']

TZOFFSET = {}

UTCZONE = ['UTC', 'GMT', 'Z', 'z']

WEEKDAYS = [('Mon', 'Monday'), ('Tue', 'Tuesday'), ('Wed', 'Wednesday'), ('Thu', 'Thursday'), ('Fri', 'Friday'), ('Sat', 'Saturday'), ('Sun', 'Sunday')]

ampm(name)

convertyear(year, century_specified=False)

Converts two-digit years to year within [-50, 49] range of self._year (current local time)

hms(name)

jump(name)

month(name)

pertain(name)

tzoffset(name)

utczone(name)

validate(res)

weekday(name)

Warnings and Exceptions

class dateutil.parser.ParserError

Exception subclass used for any failure to parse a datetime string.

This is a subclass of ValueError, and should be raised any time earlier versions of dateutil would have raised ValueError.

New in version 2.8.1.

class dateutil.parser.UnknownTimezoneWarning

Raised when the parser finds a timezone it cannot parse into a tzinfo.

New in version 2.7.0.