Current File : //usr/lib/python3/dist-packages/dateutil/parser/isoparser.py
# -*- coding: utf-8 -*-
"""
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):
# If it's a stream, read the whole thing
str_in = getattr(str_in, 'read', lambda: str_in)()
# If it's unicode, turn it into bytes, since ISO-8601 only covers ASCII
if isinstance(str_in, six.text_type):
# ASCII is the same in UTF-8
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`` or ``YYYYMM``
- ``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)
# Constants
_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')
# Year
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
# Month
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
# Day
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')
# All ISO formats start with the year
year = int(dt_str[0:4])
has_sep = dt_str[4:5] == self._DATE_SEP
pos = 4 + has_sep # Skip '-' if it's there
if dt_str[pos:pos + 1] == b'W':
# YYYY-?Www-?D?
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:
# YYYYDDD or YYYY-DDD
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: # Range is 1-7
raise ValueError('Invalid weekday: {}'.format(day))
# Get week 1 for the specific year:
jan_4 = date(year, 1, 4) # Week 1 always has January 4th in it
week_1 = jan_4 - timedelta(days=jan_4.isocalendar()[2] - 1)
# Now add the specific number of weeks and days to get what we want
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':
# Detect time zone boundary
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:
# Hour, minute, second
components[comp] = int(timestr[pos:pos + 2])
pos += 2
if comp == 3:
# Fraction of a second
frac = self._FRACTION_REGEX.match(timestr[pos:])
if not frac:
continue
us_str = frac.group(1)[:6] # Truncate to microseconds
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:
# Standard supports 00:00 and 24:00 as representations of midnight
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
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