def from_stream(cls, stream, offset=None, byte_order=LITTLE_ENDIAN):
"""Creates a ``datetime`` object from a stream.
:type stream: :class:`lf.dec.IStream`
:param stream: A stream that contains the Variant timestamp.
:type offset: ``int`` or ``None``
:param offset: The start of the Variant timestamp in the stream.
:type byte_order: constant
:param byte_order: The byte order to use (from :mod:`lf.dtypes`)
:raises ValueError: If the Variant timestamp is invalid.
:rtype: ``datetime``
:returns: The corresponding ``datetime`` object.
"""
if offset is not None:
stream.seek(offset, SEEK_SET)
# end if
if byte_order == LITTLE_ENDIAN:
vtime = float64_le.from_buffer_copy(stream.read(8)).value
else:
vtime = float64_be.from_buffer_copy(stream.read(8)).value
# end if
return cls.from_float(vtime)
def from_stream(cls, stream, offset=None, byte_order=LITTLE_ENDIAN):
"""Creates a ``datetime`` object from a stream.
:type stream: :class:`lf.dec.IStream`
:param stream: A stream that contains the Variant timestamp.
:type offset: ``int`` or ``None``
:param offset: The start of the Variant timestamp in the stream.
:type byte_order: constant
:param byte_order: The byte order to use (from :mod:`lf.dtypes`)
:raises ValueError: If the Variant timestamp is invalid.
:rtype: ``datetime``
:returns: The corresponding ``datetime`` object.
"""
if offset is not None:
stream.seek(offset, SEEK_SET)
# end if
if byte_order == LITTLE_ENDIAN:
vtime = float64_le.from_buffer_copy(stream.read(8)).value
else:
vtime = float64_be.from_buffer_copy(stream.read(8)).value
# end if
return cls.from_float(vtime)
def float64_le(self, offset=None):
"""Reads a 64-bit floating point number (little endian).
:type offset: :class:`int` or :keyword:`None`
:param offset: The start of the floating point number.
:except ValueError: if :attr:`stream` (starting at :attr:`offset` is
too small.)
:rtype: :class:`float`
:returns: The corresponding value.
"""
if offset is not None:
self.stream.seek(offset, SEEK_SET)
# end if
return float64_le.from_buffer_copy(self.stream.read(8)).value
