Major restructuring to get automatic decoding/encoding

[pycalendar.git] / pycalendar / dtype / datetime.py

diff --git a/pycalendar/dtype/datetime.py b/pycalendar/dtype/datetime.py
new file mode 100644 (file)
index 0000000..42b4934
--- /dev/null
+++ b/pycalendar/dtype/datetime.py
@@ -0,0 +1,100 @@
+# Copyright
+
+"""Functions for processing dates with times
+
+As defined in :RFC:`5545`, section 3.3.5 (Date-Time).
+"""
+
+import datetime as _datetime
+
+from . import base as _base
+from . import date as _date
+from . import time as _time
+
+
+class DateTime (_base.DataType):
+    name = 'DATE-TIME'
+
+    @classmethod
+    def decode(cls, property, value):
+        """Parse dates with times
+
+        As defined in :RFC:`5545`, section 3.3.5 (Date-Time).
+
+        >>> import pytz
+
+        >>> DateTime.decode(property={}, value='19980118T230000')
+        datetime.datetime(1998, 1, 18, 23, 0)
+        >>> DateTime.decode(property={}, value='19980119T070000Z')
+        datetime.datetime(1998, 1, 19, 7, 0, tzinfo=datetime.timezone.utc)
+
+        The following represents 2:00 A.M. in New York on January 19,
+        1998:
+
+        >>> ny = {'TZID': 'America/New_York'}
+        >>> DateTime.decode(property=ny, value='19980119T020000')
+        ... # doctest: +NORMALIZE_WHITESPACE
+        datetime.datetime(1998, 1, 19, 2, 0,
+          tzinfo=<DstTzInfo 'America/New_York' EST-1 day, 19:00:00 STD>)
+
+        If, based on the definition of the referenced time zone, the local
+        time described occurs more than once (when changing from daylight
+        to standard time), the ``DATE-TIME`` value refers to the first
+        occurrence of the referenced time.  Thus,
+        ``TZID=America/New_York:20071104T013000`` indicates November 4,
+        2007 at 1:30 A.M.  EDT (UTC-04:00).
+
+        >>> DateTime.decode(property=ny, value='20071104T013000')
+        ... # doctest: +NORMALIZE_WHITESPACE
+        datetime.datetime(2007, 11, 4, 1, 30,
+          tzinfo=<DstTzInfo 'America/New_York' EST-1 day, 19:00:00 STD>)
+
+        If the local time described does not occur (when changing from
+        standard to daylight time), the ``DATE-TIME`` value is interpreted
+        using the UTC offset before the gap in local times.  Thus,
+        ``TZID=America/New_York:20070311T023000`` indicates March 11, 2007
+        at 3:30 A.M. EDT (UTC-04:00), one hour after 1:30 A.M. EST
+        (UTC-05:00).
+
+        >>> DateTime.decode(property=ny, value='20070311T023000')
+        ... # doctest: +NORMALIZE_WHITESPACE
+        datetime.datetime(2007, 3, 11, 2, 30,
+          tzinfo=<DstTzInfo 'America/New_York' EST-1 day, 19:00:00 STD>)
+
+        A time value MUST only specify the second 60 when specifying a
+        positive leap second.  For example:
+
+        >>> DateTime.decode(property={}, value='19970630T235960Z')
+        datetime.datetime(1997, 6, 30, 23, 59, 59, tzinfo=datetime.timezone.utc)
+
+        Implementations that do not support leap seconds SHOULD interpret
+        the second 60 as equivalent to the second 59.
+
+        The following represents July 14, 1997, at 1:30 PM in New York
+        City in each of the three time formats
+
+        >>> DateTime.decode(property={}, value='19970714T133000')
+        datetime.datetime(1997, 7, 14, 13, 30)
+        >>> d = DateTime.decode(property={}, value='19970714T173000Z')
+        >>> d
+        datetime.datetime(1997, 7, 14, 17, 30, tzinfo=datetime.timezone.utc)
+        >>> d.astimezone(pytz.timezone('America/New_York'))
+        ... # doctest: +NORMALIZE_WHITESPACE
+        datetime.datetime(1997, 7, 14, 13, 30,
+          tzinfo=<DstTzInfo 'America/New_York' EDT-1 day, 20:00:00 DST>)
+        >>> DateTime.decode(property=ny, value='19970714T133000')
+        ... # doctest: +NORMALIZE_WHITESPACE
+        datetime.datetime(1997, 7, 14, 13, 30,
+          tzinfo=<DstTzInfo 'America/New_York' EST-1 day, 19:00:00 STD>)
+        """
+        date,time = value.split('T')
+        date = _date.Date.decode(property=property, value=date)
+        time = _time.Time.decode(property=property, value=time)
+        return _datetime.datetime.combine(date=date, time=time)
+
+    @classmethod
+    def encode(cls, property, value):
+        return '{}T{}'.format(
+            _date.Date.encode(property=property, value=value.date()),
+            _time.Time.encode(property=property, value=value.timetz()),
+            )