from typing import Dict
import datetime
import os
from . import config
from .instant_ import Instant
from .period_ import Period
[docs]def instant(instant):
"""Return a new instant, aka a triple of integers (year, month, day).
>>> instant(2014)
Instant((2014, 1, 1))
>>> instant('2014')
Instant((2014, 1, 1))
>>> instant('2014-02')
Instant((2014, 2, 1))
>>> instant('2014-3-2')
Instant((2014, 3, 2))
>>> instant(instant('2014-3-2'))
Instant((2014, 3, 2))
>>> instant(period('month', '2014-3-2'))
Instant((2014, 3, 2))
>>> instant(None)
"""
if instant is None:
return None
if isinstance(instant, Instant):
return instant
if isinstance(instant, str):
if not config.INSTANT_PATTERN.match(instant):
raise ValueError("'{}' is not a valid instant. Instants are described using the 'YYYY-MM-DD' format, for instance '2015-06-15'.".format(instant))
instant = Instant(
int(fragment)
for fragment in instant.split('-', 2)[:3]
)
elif isinstance(instant, datetime.date):
instant = Instant((instant.year, instant.month, instant.day))
elif isinstance(instant, int):
instant = (instant,)
elif isinstance(instant, list):
assert 1 <= len(instant) <= 3
instant = tuple(instant)
elif isinstance(instant, Period):
instant = instant.start
else:
assert isinstance(instant, tuple), instant
assert 1 <= len(instant) <= 3
if len(instant) == 1:
return Instant((instant[0], 1, 1))
if len(instant) == 2:
return Instant((instant[0], instant[1], 1))
return Instant(instant)
def instant_date(instant):
if instant is None:
return None
instant_date = config.date_by_instant_cache.get(instant)
if instant_date is None:
config.date_by_instant_cache[instant] = instant_date = datetime.date(*instant)
return instant_date
[docs]def period(value) -> Period:
"""Return a new period, aka a triple (unit, start_instant, size).
>>> period('2014')
Period((YEAR, Instant((2014, 1, 1)), 1))
>>> period('year:2014')
Period((YEAR, Instant((2014, 1, 1)), 1))
>>> period('2014-2')
Period((MONTH, Instant((2014, 2, 1)), 1))
>>> period('2014-02')
Period((MONTH, Instant((2014, 2, 1)), 1))
>>> period('month:2014-2')
Period((MONTH, Instant((2014, 2, 1)), 1))
>>> period('year:2014-2')
Period((YEAR, Instant((2014, 2, 1)), 1))
"""
if isinstance(value, Period):
return value
if isinstance(value, Instant):
return Period((config.DAY, value, 1))
def parse_simple_period(value):
"""
Parses simple periods respecting the ISO format, such as 2012 or 2015-03
"""
try:
date = datetime.datetime.strptime(value, '%Y')
except ValueError:
try:
date = datetime.datetime.strptime(value, '%Y-%m')
except ValueError:
try:
date = datetime.datetime.strptime(value, '%Y-%m-%d')
except ValueError:
return None
else:
return Period((config.DAY, Instant((date.year, date.month, date.day)), 1))
else:
return Period((config.MONTH, Instant((date.year, date.month, 1)), 1))
else:
return Period((config.YEAR, Instant((date.year, date.month, 1)), 1))
def raise_error(value):
message = os.linesep.join([
"Expected a period (eg. '2017', '2017-01', '2017-01-01', ...); got: '{}'.".format(value),
"Learn more about legal period formats in OpenFisca:",
"<https://openfisca.org/doc/coding-the-legislation/35_periods.html#periods-in-simulations>."
])
raise ValueError(message)
if value == 'ETERNITY' or value == config.ETERNITY:
return Period(('eternity', instant(datetime.date.min), float("inf")))
# check the type
if isinstance(value, int):
return Period((config.YEAR, Instant((value, 1, 1)), 1))
if not isinstance(value, str):
raise_error(value)
# try to parse as a simple period
period = parse_simple_period(value)
if period is not None:
return period
# complex period must have a ':' in their strings
if ":" not in value:
raise_error(value)
components = value.split(':')
# left-most component must be a valid unit
unit = components[0]
if unit not in (config.DAY, config.MONTH, config.YEAR):
raise_error(value)
# middle component must be a valid iso period
base_period = parse_simple_period(components[1])
if not base_period:
raise_error(value)
# period like year:2015-03 have a size of 1
if len(components) == 2:
size = 1
# if provided, make sure the size is an integer
elif len(components) == 3:
try:
size = int(components[2])
except ValueError:
raise_error(value)
# if there is more than 2 ":" in the string, the period is invalid
else:
raise_error(value)
# reject ambiguous period such as month:2014
if unit_weight(base_period.unit) > unit_weight(unit):
raise_error(value)
return Period((unit, base_period.start, size))
[docs]def key_period_size(period):
"""
Defines a key in order to sort periods by length. It uses two aspects : first unit then size
:param period: an OpenFisca period
:return: a string
>>> key_period_size(period('2014'))
'2_1'
>>> key_period_size(period('2013'))
'2_1'
>>> key_period_size(period('2014-01'))
'1_1'
"""
unit, start, size = period
return '{}_{}'.format(unit_weight(unit), size)
def unit_weights() -> Dict[str, int]:
return {
config.DAY: 100,
config.MONTH: 200,
config.YEAR: 300,
config.ETERNITY: 400,
}
def unit_weight(unit: str) -> int:
return unit_weights()[unit]