Source code for geetools.Date
"""Extra methods for the ``ee.Date`` class."""
from __future__ import annotations
from datetime import datetime
import ee
from geetools.accessors import register_class_accessor
[docs]
EE_EPOCH = datetime(1970, 1, 1, 0, 0, 0)
@register_class_accessor(ee.Date, "geetools")
class DateAccessor:
"""Toolbox for the ``ee.Date`` class."""
def __init__(self, obj: ee.Date):
"""Initialize the Date class."""
self._obj = obj
# -- alternative constructor -----------------------------------------------
@classmethod
def fromEpoch(cls, number: int, unit: str = "day") -> ee.Date:
"""Set an the number of units since epoch (1970-01-01).
Parameters:
number: The number of units since the epoch.
unit: The unit to return the number of. One of: ``second``, ``minute``, ``hour``, ``day``, ``month``, ``year``.
Returns:
The date as a ``ee.Date`` object.
Examples:
.. code-block:: python
import ee, geetools
ee.Initialize()
d = ee.Date.geetools.fromEpoch(49, 'year')
d.getInfo()
"""
cls.check_unit(unit)
return ee.Date(EE_EPOCH.isoformat()).advance(number, unit)
@classmethod
def fromDOY(cls, doy: int, year: int) -> ee.Date:
"""Create a date from a day of year and a year.
Parameters:
doy: The day of year.
year: The year.
Returns:
The date as a ``ee.Date`` object.
Examples:
.. code-block:: python
import ee, geetools
ee.Initialize()
d = ee.Date.geetools.fromDOY(1, 2020)
d.getInfo()
"""
d, y = ee.Number(doy).toInt(), ee.Number(year).toInt()
return ee.Date.fromYMD(y, 1, 1).advance(d.subtract(1), "day")
# -- export date -----------------------------------------------------------
def to_datetime(self) -> datetime:
"""Convert a ``ee.Date`` to a ``datetime.datetime``.
Returns:
The ``datetime.datetime`` representation of the ``ee.Date``.
Examples:
.. code-block:: python
import ee, geetools
ee.Initialize()
d = ee.Date('2020-01-01').geetools.toDatetime()
d.strftime('%Y-%m-%d')
"""
return datetime.fromtimestamp(self._obj.millis().getInfo() / 1000.0)
# -- date operations -------------------------------------------------------
def getUnitSinceEpoch(self, unit: str = "day") -> ee.Number:
"""Get the number of units since epoch (1970-01-01).
Parameters:
unit: The unit to return the number of. One of: ``second``, ``minute``, ``hour``, ``day``, ``month``, ``year``.
Returns:
The number of units since the epoch.
Examples:
.. code-block:: python
import ee, geetools
ee.Initialize()
d = ee.Date('2020-01-01').geetools.getUnitSinceEpoch('year')
d.getInfo()
"""
self.check_unit(unit)
return self._obj.difference(EE_EPOCH, unit).toInt()
def isLeap(self) -> ee.Number:
"""Check if the year of the date is a leap year.
Returns:
``1`` if the year is a leap year, ``0`` otherwise.
Examples:
.. code-block:: python
import ee, geetools
ee.Initialize()
d = ee.Date('2020-01-01').geetools.isLeap()
d.getInfo()
"""
year = self._obj.get("year")
divisibleBy4 = year.mod(4).eq(0)
divisibleBy100 = year.mod(100).eq(0)
divisibleBy400 = year.mod(400).eq(0)
# d400 or (d4 and not d100)
isLeap = divisibleBy400.Or(divisibleBy4.And(divisibleBy100.Not()))
return isLeap.toInt()
# -- helper methods --------------------------------------------------------
@staticmethod
def check_unit(unit: str) -> None:
"""Check if the provided value is a valid time unit."""
if unit not in (units := ["second", "minute", "hour", "day", "month", "year"]):
raise ValueError(f"unit must be one of: {','.join(units)}")