| | |
| | """ |
| | This module offers a parser for ISO-8601 strings |
| | |
| | It is intended to support all valid date, time and datetime formats per the |
| | ISO-8601 specification. |
| | |
| | ..versionadded:: 2.7.0 |
| | """ |
| | from datetime import datetime, timedelta, time, date |
| | import calendar |
| | from dateutil import tz |
| |
|
| | from functools import wraps |
| |
|
| | import re |
| | import six |
| |
|
| | __all__ = ["isoparse", "isoparser"] |
| |
|
| |
|
| | def _takes_ascii(f): |
| | @wraps(f) |
| | def func(self, str_in, *args, **kwargs): |
| | |
| | str_in = getattr(str_in, 'read', lambda: str_in)() |
| |
|
| | |
| | if isinstance(str_in, six.text_type): |
| | |
| | try: |
| | str_in = str_in.encode('ascii') |
| | except UnicodeEncodeError as e: |
| | msg = 'ISO-8601 strings should contain only ASCII characters' |
| | six.raise_from(ValueError(msg), e) |
| |
|
| | return f(self, str_in, *args, **kwargs) |
| |
|
| | return func |
| |
|
| |
|
| | class isoparser(object): |
| | def __init__(self, sep=None): |
| | """ |
| | :param sep: |
| | A single character that separates date and time portions. If |
| | ``None``, the parser will accept any single character. |
| | For strict ISO-8601 adherence, pass ``'T'``. |
| | """ |
| | if sep is not None: |
| | if (len(sep) != 1 or ord(sep) >= 128 or sep in '0123456789'): |
| | raise ValueError('Separator must be a single, non-numeric ' + |
| | 'ASCII character') |
| |
|
| | sep = sep.encode('ascii') |
| |
|
| | self._sep = sep |
| |
|
| | @_takes_ascii |
| | def isoparse(self, dt_str): |
| | """ |
| | Parse an ISO-8601 datetime string into a :class:`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 |
| | :func:`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 :class:`dateutil.tz.tzoffset` objects, |
| | with the exception of UTC, which will be represented as |
| | :class:`dateutil.tz.tzutc`. Time zone offsets equivalent to UTC (such |
| | as `+00:00`) will also be represented as :class:`dateutil.tz.tzutc`. |
| | |
| | :param dt_str: |
| | A string or stream containing only an ISO-8601 datetime string |
| | |
| | :return: |
| | Returns a :class:`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. |
| | |
| | .. versionadded:: 2.7.0 |
| | """ |
| | components, pos = self._parse_isodate(dt_str) |
| |
|
| | if len(dt_str) > pos: |
| | if self._sep is None or dt_str[pos:pos + 1] == self._sep: |
| | components += self._parse_isotime(dt_str[pos + 1:]) |
| | else: |
| | raise ValueError('String contains unknown ISO components') |
| |
|
| | if len(components) > 3 and components[3] == 24: |
| | components[3] = 0 |
| | return datetime(*components) + timedelta(days=1) |
| |
|
| | return datetime(*components) |
| |
|
| | @_takes_ascii |
| | def parse_isodate(self, datestr): |
| | """ |
| | Parse the date portion of an ISO string. |
| | |
| | :param datestr: |
| | The string portion of an ISO string, without a separator |
| | |
| | :return: |
| | Returns a :class:`datetime.date` object |
| | """ |
| | components, pos = self._parse_isodate(datestr) |
| | if pos < len(datestr): |
| | raise ValueError('String contains unknown ISO ' + |
| | 'components: {!r}'.format(datestr.decode('ascii'))) |
| | return date(*components) |
| |
|
| | @_takes_ascii |
| | def parse_isotime(self, timestr): |
| | """ |
| | Parse the time portion of an ISO string. |
| | |
| | :param timestr: |
| | The time portion of an ISO string, without a separator |
| | |
| | :return: |
| | Returns a :class:`datetime.time` object |
| | """ |
| | components = self._parse_isotime(timestr) |
| | if components[0] == 24: |
| | components[0] = 0 |
| | return time(*components) |
| |
|
| | @_takes_ascii |
| | def parse_tzstr(self, tzstr, zero_as_utc=True): |
| | """ |
| | Parse a valid ISO time zone string. |
| | |
| | See :func:`isoparser.isoparse` for details on supported formats. |
| | |
| | :param tzstr: |
| | A string representing an ISO time zone offset |
| | |
| | :param zero_as_utc: |
| | Whether to return :class:`dateutil.tz.tzutc` for zero-offset zones |
| | |
| | :return: |
| | Returns :class:`dateutil.tz.tzoffset` for offsets and |
| | :class:`dateutil.tz.tzutc` for ``Z`` and (if ``zero_as_utc`` is |
| | specified) offsets equivalent to UTC. |
| | """ |
| | return self._parse_tzstr(tzstr, zero_as_utc=zero_as_utc) |
| |
|
| | |
| | _DATE_SEP = b'-' |
| | _TIME_SEP = b':' |
| | _FRACTION_REGEX = re.compile(b'[\\.,]([0-9]+)') |
| |
|
| | def _parse_isodate(self, dt_str): |
| | try: |
| | return self._parse_isodate_common(dt_str) |
| | except ValueError: |
| | return self._parse_isodate_uncommon(dt_str) |
| |
|
| | def _parse_isodate_common(self, dt_str): |
| | len_str = len(dt_str) |
| | components = [1, 1, 1] |
| |
|
| | if len_str < 4: |
| | raise ValueError('ISO string too short') |
| |
|
| | |
| | components[0] = int(dt_str[0:4]) |
| | pos = 4 |
| | if pos >= len_str: |
| | return components, pos |
| |
|
| | has_sep = dt_str[pos:pos + 1] == self._DATE_SEP |
| | if has_sep: |
| | pos += 1 |
| |
|
| | |
| | if len_str - pos < 2: |
| | raise ValueError('Invalid common month') |
| |
|
| | components[1] = int(dt_str[pos:pos + 2]) |
| | pos += 2 |
| |
|
| | if pos >= len_str: |
| | if has_sep: |
| | return components, pos |
| | else: |
| | raise ValueError('Invalid ISO format') |
| |
|
| | if has_sep: |
| | if dt_str[pos:pos + 1] != self._DATE_SEP: |
| | raise ValueError('Invalid separator in ISO string') |
| | pos += 1 |
| |
|
| | |
| | if len_str - pos < 2: |
| | raise ValueError('Invalid common day') |
| | components[2] = int(dt_str[pos:pos + 2]) |
| | return components, pos + 2 |
| |
|
| | def _parse_isodate_uncommon(self, dt_str): |
| | if len(dt_str) < 4: |
| | raise ValueError('ISO string too short') |
| |
|
| | |
| | year = int(dt_str[0:4]) |
| |
|
| | has_sep = dt_str[4:5] == self._DATE_SEP |
| |
|
| | pos = 4 + has_sep |
| | if dt_str[pos:pos + 1] == b'W': |
| | |
| | pos += 1 |
| | weekno = int(dt_str[pos:pos + 2]) |
| | pos += 2 |
| |
|
| | dayno = 1 |
| | if len(dt_str) > pos: |
| | if (dt_str[pos:pos + 1] == self._DATE_SEP) != has_sep: |
| | raise ValueError('Inconsistent use of dash separator') |
| |
|
| | pos += has_sep |
| |
|
| | dayno = int(dt_str[pos:pos + 1]) |
| | pos += 1 |
| |
|
| | base_date = self._calculate_weekdate(year, weekno, dayno) |
| | else: |
| | |
| | if len(dt_str) - pos < 3: |
| | raise ValueError('Invalid ordinal day') |
| |
|
| | ordinal_day = int(dt_str[pos:pos + 3]) |
| | pos += 3 |
| |
|
| | if ordinal_day < 1 or ordinal_day > (365 + calendar.isleap(year)): |
| | raise ValueError('Invalid ordinal day' + |
| | ' {} for year {}'.format(ordinal_day, year)) |
| |
|
| | base_date = date(year, 1, 1) + timedelta(days=ordinal_day - 1) |
| |
|
| | components = [base_date.year, base_date.month, base_date.day] |
| | return components, pos |
| |
|
| | def _calculate_weekdate(self, year, week, day): |
| | """ |
| | Calculate the day of corresponding to the ISO year-week-day calendar. |
| | |
| | This function is effectively the inverse of |
| | :func:`datetime.date.isocalendar`. |
| | |
| | :param year: |
| | The year in the ISO calendar |
| | |
| | :param week: |
| | The week in the ISO calendar - range is [1, 53] |
| | |
| | :param day: |
| | The day in the ISO calendar - range is [1 (MON), 7 (SUN)] |
| | |
| | :return: |
| | Returns a :class:`datetime.date` |
| | """ |
| | if not 0 < week < 54: |
| | raise ValueError('Invalid week: {}'.format(week)) |
| |
|
| | if not 0 < day < 8: |
| | raise ValueError('Invalid weekday: {}'.format(day)) |
| |
|
| | |
| | jan_4 = date(year, 1, 4) |
| | week_1 = jan_4 - timedelta(days=jan_4.isocalendar()[2] - 1) |
| |
|
| | |
| | week_offset = (week - 1) * 7 + (day - 1) |
| | return week_1 + timedelta(days=week_offset) |
| |
|
| | def _parse_isotime(self, timestr): |
| | len_str = len(timestr) |
| | components = [0, 0, 0, 0, None] |
| | pos = 0 |
| | comp = -1 |
| |
|
| | if len_str < 2: |
| | raise ValueError('ISO time too short') |
| |
|
| | has_sep = False |
| |
|
| | while pos < len_str and comp < 5: |
| | comp += 1 |
| |
|
| | if timestr[pos:pos + 1] in b'-+Zz': |
| | |
| | components[-1] = self._parse_tzstr(timestr[pos:]) |
| | pos = len_str |
| | break |
| |
|
| | if comp == 1 and timestr[pos:pos+1] == self._TIME_SEP: |
| | has_sep = True |
| | pos += 1 |
| | elif comp == 2 and has_sep: |
| | if timestr[pos:pos+1] != self._TIME_SEP: |
| | raise ValueError('Inconsistent use of colon separator') |
| | pos += 1 |
| |
|
| | if comp < 3: |
| | |
| | components[comp] = int(timestr[pos:pos + 2]) |
| | pos += 2 |
| |
|
| | if comp == 3: |
| | |
| | frac = self._FRACTION_REGEX.match(timestr[pos:]) |
| | if not frac: |
| | continue |
| |
|
| | us_str = frac.group(1)[:6] |
| | components[comp] = int(us_str) * 10**(6 - len(us_str)) |
| | pos += len(frac.group()) |
| |
|
| | if pos < len_str: |
| | raise ValueError('Unused components in ISO string') |
| |
|
| | if components[0] == 24: |
| | |
| | if any(component != 0 for component in components[1:4]): |
| | raise ValueError('Hour may only be 24 at 24:00:00.000') |
| |
|
| | return components |
| |
|
| | def _parse_tzstr(self, tzstr, zero_as_utc=True): |
| | if tzstr == b'Z' or tzstr == b'z': |
| | return tz.UTC |
| |
|
| | if len(tzstr) not in {3, 5, 6}: |
| | raise ValueError('Time zone offset must be 1, 3, 5 or 6 characters') |
| |
|
| | if tzstr[0:1] == b'-': |
| | mult = -1 |
| | elif tzstr[0:1] == b'+': |
| | mult = 1 |
| | else: |
| | raise ValueError('Time zone offset requires sign') |
| |
|
| | hours = int(tzstr[1:3]) |
| | if len(tzstr) == 3: |
| | minutes = 0 |
| | else: |
| | minutes = int(tzstr[(4 if tzstr[3:4] == self._TIME_SEP else 3):]) |
| |
|
| | if zero_as_utc and hours == 0 and minutes == 0: |
| | return tz.UTC |
| | else: |
| | if minutes > 59: |
| | raise ValueError('Invalid minutes in time zone offset') |
| |
|
| | if hours > 23: |
| | raise ValueError('Invalid hours in time zone offset') |
| |
|
| | return tz.tzoffset(None, mult * (hours * 60 + minutes) * 60) |
| |
|
| |
|
| | DEFAULT_ISOPARSER = isoparser() |
| | isoparse = DEFAULT_ISOPARSER.isoparse |
| |
|