columns.py 文件源码

def to_excel(self, value):
        if type(value) == date:
            value = datetime.combine(value, time.min)
        if not isinstance(value, datetime):
            raise UnableToParseDatetime(value=value)

        delta = (value - datetime(year=1900, month=1, day=1))
        value = delta.days + delta.seconds / self.SECONDS_PER_DAY + 2

        # Excel incorrectly assumes 1900 to be a leap year.
        if value < 61:
            if value < 1:
                raise UnableToParseDatetime(value=value)
            value -= 1
        return value