weboob-devel/weboob/tools/date.py
2013-04-03 19:04:56 +02:00

201 lines
6.7 KiB
Python

# -*- coding: utf-8 -*-
# Copyright(C) 2010-2013 Romain Bignon
#
# This file is part of weboob.
#
# weboob is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# weboob is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with weboob. If not, see <http://www.gnu.org/licenses/>.
from datetime import date as real_date, datetime as real_datetime, timedelta
import time
import re
try:
from dateutil import tz
except ImportError:
raise ImportError('Please install python-dateutil')
__all__ = ['local2utc', 'utc2local', 'LinearDateGuesser', 'date', 'datetime', 'new_date', 'new_datetime']
def local2utc(dateobj):
dateobj = dateobj.replace(tzinfo=tz.tzlocal())
dateobj = dateobj.astimezone(tz.tzutc())
return dateobj
def utc2local(dateobj):
dateobj = dateobj.replace(tzinfo=tz.tzutc())
dateobj = dateobj.astimezone(tz.tzlocal())
return dateobj
class date(real_date):
def strftime(self, fmt):
return strftime(self, fmt)
class datetime(real_datetime):
def strftime(self, fmt):
return strftime(self, fmt)
def combine(self, date, time):
return datetime(date.year, date.month, date.day, time.hour, time.minute, time.microsecond, time.tzinfo)
def date(self):
return date(self.year, self.month, self.day)
def new_date(d):
""" Generate a safe date from a datetime.date object """
return date(d.year, d.month, d.day)
def new_datetime(d):
"""
Generate a safe datetime from a datetime.date or datetime.datetime object
"""
kw = [d.year, d.month, d.day]
if isinstance(d, real_datetime):
kw.extend([d.hour, d.minute, d.second, d.microsecond, d.tzinfo])
return datetime(*kw)
# No support for strftime's "%s" or "%y".
# Allowed if there's an even number of "%"s because they are escaped.
_illegal_formatting = re.compile(r"((^|[^%])(%%)*%[sy])")
def _findall(text, substr):
# Also finds overlaps
sites = []
i = 0
while 1:
j = text.find(substr, i)
if j == -1:
break
sites.append(j)
i = j+1
return sites
def strftime(dt, fmt):
if dt.year >= 1900:
return super(type(dt), dt).strftime(fmt)
illegal_formatting = _illegal_formatting.search(fmt)
if illegal_formatting:
raise TypeError("strftime of dates before 1900 does not handle" + illegal_formatting.group(0))
year = dt.year
# For every non-leap year century, advance by
# 6 years to get into the 28-year repeat cycle
delta = 2000 - year
off = 6*(delta // 100 + delta // 400)
year = year + off
# Move to around the year 2000
year = year + ((2000 - year)//28)*28
timetuple = dt.timetuple()
s1 = time.strftime(fmt, (year,) + timetuple[1:])
sites1 = _findall(s1, str(year))
s2 = time.strftime(fmt, (year+28,) + timetuple[1:])
sites2 = _findall(s2, str(year+28))
sites = []
for site in sites1:
if site in sites2:
sites.append(site)
s = s1
syear = "%4d" % (dt.year,)
for site in sites:
s = s[:site] + syear + s[site+4:]
return s
class LinearDateGuesser(object):
"""
The aim of this class is to guess the exact date object from
a day and a month, but not a year.
It works with a start date (default is today), and all dates must be
sorted from recent to older.
"""
def __init__(self, current_date=None, date_max_bump=timedelta(7)):
self.date_max_bump = date_max_bump
if current_date is None:
current_date = date.today()
self.current_date = current_date
def try_assigning_year(self, day, month, start_year, max_year):
"""
Tries to create a date object with day, month and start_year and returns
it.
If it fails due to the year not matching the day+month combination
(i.e. due to a ValueError -- TypeError and OverflowError are not
handled), the previous or next years are tried until max_year is
reached.
In case initialization still fails with max_year, this function raises
a ValueError.
"""
while 1:
try:
return date(start_year, month, day)
except ValueError, e:
if start_year == max_year:
raise e
start_year += cmp(max_year, start_year)
def set_current_date(self, current_date):
self.current_date = current_date
def guess_date(self, day, month, change_current_date=True):
""" Returns a date object built from a given day/month pair. """
today = self.current_date
# The website only provides dates using the 'DD/MM' string, so we have to
# determine the most possible year by ourselves. This implies tracking
# the current date.
# However, we may also encounter "bumps" in the dates, e.g. "12/11,
# 10/11, 10/11, 12/11, 09/11", so we have to be, well, quite tolerant,
# by accepting dates in the near future (say, 7 days) of the current
# date. (Please, kill me...)
# We first try to keep the current year
naively_parsed_date = self.try_assigning_year(day, month, today.year, today.year - 5)
if (naively_parsed_date.year != today.year):
# we most likely hit a 29/02 leading to a change of year
if change_current_date:
self.set_current_date(naively_parsed_date)
return naively_parsed_date
if (naively_parsed_date > today + self.date_max_bump):
# if the date ends up too far in the future, consider it actually
# belongs to the previous year
parsed_date = date(today.year - 1, month, day)
if change_current_date:
self.set_current_date(parsed_date)
elif (naively_parsed_date > today and naively_parsed_date <= today + self.date_max_bump):
# if the date is in the near future, consider it is a bump
parsed_date = naively_parsed_date
# do not keep it as current date though
else:
# if the date is in the past, as expected, simply keep it
parsed_date = naively_parsed_date
# and make it the new current date
if change_current_date:
self.set_current_date(parsed_date)
return parsed_date