is_shabbos_or_yt.py

#!/usr/bin/python
import datetime
import json
import urllib2
import re
import pytz

# django utilites for parsing datetime
class FixedOffset(datetime.tzinfo):
	"""
	Fixed offset in minutes east from UTC. Taken from Python's docs.

	Kept as close as possible to the reference version. __init__ was changed
	to make its arguments optional, according to Python's requirement that
	tzinfo subclasses can be instantiated without arguments.
	"""

	def __init__(self, offset=None, name=None):
		if offset is not None:
			self.__offset = datetime.timedelta(minutes=offset)
		if name is not None:
			self.__name = name

	def utcoffset(self, dt):
		return self.__offset

	def tzname(self, dt):
		return self.__name

	def dst(self, dt):
		return ZERO

def get_fixed_timezone(offset):
	"""
	Returns a tzinfo instance with a fixed offset from UTC.
	"""
	if isinstance(offset, datetime.timedelta):
		offset = offset.seconds // 60
	sign = '-' if offset < 0 else '+'
	hhmm = '%02d%02d' % divmod(abs(offset), 60)
	name = sign + hhmm
	return FixedOffset(offset, name)
	
def parse_date(value):
	"""Parses a string and return a datetime.date.

	Raises ValueError if the input is well formatted but not a valid date.
	Returns None if the input isn't well formatted.
	"""
	date_re = re.compile(
	r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})$'
)
	match = date_re.match(value)
	if match:
		kw = {k: int(v) for k, v in dict.iteritems(match.groupdict())}
		return datetime.date(**kw)
		
def parse_datetime(value):
	"""Parses a string and return a datetime.datetime.

	This function supports time zone offsets. When the input contains one,
	the output uses a timezone with a fixed offset from UTC.

	Raises ValueError if the input is well formatted but not a valid datetime.
	Returns None if the input isn't well formatted.
	"""
	datetime_re = re.compile(
	r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})'
	r'[T ](?P<hour>\d{1,2}):(?P<minute>\d{1,2})'
	r'(?::(?P<second>\d{1,2})(?:\.(?P<microsecond>\d{1,6})\d{0,6})?)?'
	r'(?P<tzinfo>Z|[+-]\d{2}(?::?\d{2})?)?$'
)
	match = datetime_re.match(value)
	if match:
		kw = match.groupdict()
		if kw['microsecond']:
			kw['microsecond'] = kw['microsecond'].ljust(6, '0')
		tzinfo = kw.pop('tzinfo')
		if tzinfo == 'Z':
			tzinfo = utc
		elif tzinfo is not None:
			offset_mins = int(tzinfo[-2:]) if len(tzinfo) > 3 else 0
			offset = 60 * int(tzinfo[1:3]) + offset_mins
			if tzinfo[0] == '-':
				offset = -offset
			tzinfo = get_fixed_timezone(offset)
		kw = {k: int(v) for k, v in dict.iteritems(kw) if v is not None}
		kw['tzinfo'] = tzinfo
		return datetime.datetime(**kw)

# here's the relevant code
def is_shabbos_or_yt(day, zip_code):
	url = 'http://www.hebcal.com/hebcal/?v=1&cfg=json&maj=on&min=off&mod=off&nx=off&year=now&month=x&ss=off&mf=off&c=on&b=18&m=72&geo=zip&zip={0}&m=50&s=off=&d=off&D=off&o=off'.format(zip_code)
	try:
		heb_dates = json.load(urllib2.urlopen(url, timeout=5))
	except:
		return False
	holidays = [i for i in heb_dates['items'] if i['category'] == 'holiday']
	candles = [i for i in heb_dates['items'] if i['category'] == 'candles']
	havdalah = [i for i in heb_dates['items'] if i['category'] == 'havdalah']
	today = day
	after_candlelighting = [i for i in candles if parse_datetime(i['date']).date() == today.date() and parse_datetime(i['date']) <= today]
	before_havdala = [i for i in havdalah if parse_datetime(i['date']).date() == today.date() and parse_datetime(i['date']) >= today]
	today_holiday = [i for i in holidays if i.get('yomtov') and parse_date(i['date'].split('T')[0]) == today.date()] #sometimes hebcal sends a datetime
	return (len(after_candlelighting) or len(today_holiday) or len(before_havdala))
  

if __name__ == '__main__':	
	now = datetime.datetime.utcnow().replace(tzinfo=pytz.utc)
	print now
	print is_shabbos_or_yt(now, zip_code='10018')