class DbfDateFieldDef(DbfFieldDef):
"""Definition of the date field."""
typeCode = "D"
defaultValue = utils.classproperty(lambda cls: datetime.date.today())
# "yyyymmdd" gives us 8 characters
length = 8
def decodeValue(self, value):
"""Return a ``datetime.date`` instance decoded from ``value``."""
if value.strip():
return utils.getDate(value)
else:
return None
def encodeValue(self, value):
"""Return a string-encoded value.
``value`` argument should be a value suitable for the
`utils.getDate` call.
Return:
Return value is a string in format "yyyymmdd".
"""
if value:
return utils.getDate(value).strftime("%Y%m%d")
else:
return " " * self.length
class DbfDateTimeFieldDef(DbfFieldDef):
"""Definition of the timestamp field."""
# a difference between JDN (Julian Day Number)
# and GDN (Gregorian Day Number). note, that GDN < JDN
JDN_GDN_DIFF = 1721425
typeCode = "T"
defaultValue = utils.classproperty(lambda cls: datetime.datetime.now())
# two 32-bits integers representing JDN and amount of
# milliseconds respectively gives us 8 bytes.
# note, that values must be encoded in LE byteorder.
length = 8
def decodeValue(self, value):
"""Return a `datetime.datetime` instance."""
assert len(value) == self.length
# LE byteorder
_jdn, _msecs = struct.unpack("<2I", value)
if _jdn >= 1:
_rv = datetime.datetime.fromordinal(_jdn - self.JDN_GDN_DIFF)
_rv += datetime.timedelta(0, _msecs / 1000.0)
else:
# empty date
_rv = None
return _rv
def encodeValue(self, value):
"""Return a string-encoded ``value``."""
if value:
value = utils.getDateTime(value)
# LE byteorder
_rv = struct.pack(
"<2I",
value.toordinal() + self.JDN_GDN_DIFF,
(value.hour * 3600 + value.minute * 60 + value.second) * 1000)
else:
_rv = "\0" * self.length
assert len(_rv) == self.length
return _rv