Source code for dfdatetime.ole_automation_date

"""OLE automation date (or Floatingtime or Application time) implementation."""

import decimal

from dfdatetime import definitions
from dfdatetime import factory
from dfdatetime import interface


[docs] class OLEAutomationDateEpoch(interface.DateTimeEpoch): """OLE automation date epoch."""
[docs] def __init__(self): """Initializes a OLE automation date epoch.""" super().__init__(1899, 12, 30)
[docs] class OLEAutomationDate(interface.DateTimeValues): """OLE Automation date. The OLE Automation date is a floating point value that contains the number of days since 1899-12-30 (also known as the OLE Automation date epoch), and the fractional part represents the fraction of a day since midnight. Negative values represent date and times predating the OLE Automation date epoch. Also see: https://learn.microsoft.com/en-us/dotnet/api/system.datetime.tooadate?view=net-8.0 Attributes: is_local_time (bool): True if the date and time value is in local time. """ _EPOCH = OLEAutomationDateEpoch() # The difference between December 30, 1899 and January 1, 1970 in days. _OLE_AUTOMATION_DATE_TO_POSIX_BASE = 25569
[docs] def __init__(self, precision=None, time_zone_offset=None, timestamp=None): """Initializes an OLE Automation date. Args: precision (Optional[str]): precision of the date and time value, which should be one of the PRECISION_VALUES in definitions. time_zone_offset (Optional[int]): time zone offset in number of minutes from UTC or None if not set. timestamp (Optional[float]): OLE Automation date. """ super().__init__( precision=precision or definitions.PRECISION_1_MICROSECOND, time_zone_offset=time_zone_offset, ) self._timestamp = timestamp
@property def timestamp(self): """float: OLE Automation date timestamp or None if not set.""" return self._timestamp def _GetNormalizedTimestamp(self): """Retrieves the normalized timestamp. Returns: decimal.Decimal: normalized timestamp, which contains the number of seconds since January 1, 1970 00:00:00 and a fraction of second used for increased precision, or None if the normalized timestamp cannot be determined. """ if self._normalized_timestamp is None: if self._timestamp is not None: self._normalized_timestamp = ( decimal.Decimal(self._timestamp) - self._OLE_AUTOMATION_DATE_TO_POSIX_BASE ) self._normalized_timestamp *= definitions.SECONDS_PER_DAY if self._time_zone_offset: self._normalized_timestamp -= self._time_zone_offset * 60 return self._normalized_timestamp
[docs] def CopyFromDateTimeString(self, time_string): """Copies an OLE Automation date from a date and time string. Args: time_string (str): date and time value formatted as: YYYY-MM-DD hh:mm:ss.######[+-]##:## Where # are numeric digits ranging from 0 to 9 and the seconds fraction can be either 3, 6 or 9 digits. The time of day, seconds fraction and time zone offset are optional. The default time zone is UTC. Raises: ValueError: if the time string is invalid or not supported. """ date_time_values = self._CopyDateTimeFromString(time_string) year = date_time_values.get("year", 0) month = date_time_values.get("month", 0) day_of_month = date_time_values.get("day_of_month", 0) hours = date_time_values.get("hours", 0) minutes = date_time_values.get("minutes", 0) seconds = date_time_values.get("seconds", 0) nanoseconds = date_time_values.get("nanoseconds", 0) time_zone_offset = date_time_values.get("time_zone_offset") timestamp = self._GetNumberOfSecondsFromElements( year, month, day_of_month, hours, minutes, seconds ) timestamp = float(timestamp) timestamp += float(nanoseconds) / definitions.NANOSECONDS_PER_SECOND timestamp /= definitions.SECONDS_PER_DAY timestamp += self._OLE_AUTOMATION_DATE_TO_POSIX_BASE self._normalized_timestamp = None self._timestamp = timestamp self._time_zone_offset = time_zone_offset
[docs] def CopyToDateTimeString(self): """Copies the OLE Automation date to a date and time string. Returns: str: date and time value formatted as: "YYYY-MM-DD hh:mm:ss.######" or None if the timestamp is missing. """ if self._timestamp is None: return None timestamp = self._timestamp * definitions.SECONDS_PER_DAY number_of_days, hours, minutes, seconds = self._GetTimeValues(int(timestamp)) year, month, day_of_month = self._GetDateValuesWithEpoch( number_of_days, self._EPOCH ) microseconds = int((timestamp % 1) * definitions.MICROSECONDS_PER_SECOND) return ( f"{year:04d}-{month:02d}-{day_of_month:02d} " f"{hours:02d}:{minutes:02d}:{seconds:02d}.{microseconds:06d}" )
[docs] def CopyToSerializableDict(self): """Copies the date time value to a serializable dictionary. Returns: dict[str, object]: serializable dictionary. """ serializable_dict = self._CreateSerializableDict() serializable_dict["timestamp"] = self._timestamp return serializable_dict
factory.Factory.RegisterDateTimeValues(OLEAutomationDate)