Old engine for Continuous Time Bayesian Networks. Superseded by reCTBN. 🐍
https://github.com/madlabunimib/PyCTBN
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
411 lines
13 KiB
411 lines
13 KiB
# -*- 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: {}'.format(datestr))
|
|
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(timestr) < 2:
|
|
raise ValueError('ISO time too short')
|
|
|
|
has_sep = len_str >= 3 and timestr[2:3] == self._TIME_SEP
|
|
|
|
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 < 3:
|
|
# Hour, minute, second
|
|
components[comp] = int(timestr[pos:pos + 2])
|
|
pos += 2
|
|
if (has_sep and pos < len_str and
|
|
timestr[pos:pos + 1] == self._TIME_SEP):
|
|
pos += 1
|
|
|
|
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
|
|
|