Python Durationfield django

Django 1.8中使用新DurationField的困难

对于Django的新款车型，我有点麻烦

我希望用户能够选择我的webapp上的事件持续时间是1天、3天还是5天，默认选择是3天

在我的模型开始时，我声明了以下选项：

SHORT = datetime.timedelta(days=1)
MEDIUM = datetime.timedelta(days=3)
LONG = datetime.timedelta(days=5)
DURATION_CHOICES = ((SHORT, '1 day'),(MEDIUM, '3 days'), (LONG, '5 days'),)

然后，我在下面声明DurationField：

duration = models.DurationField(choices = DURATION_CHOICES, default = MEDIUM)

我为模型创建了一个ModelForm，并将其呈现在适当的模板上。在表单上，3天是下拉列表中的预选选项，1天和5天也是选项。但是，当我提交表单时，会出现表单验证错误，请选择有效选项。3天，0:00:00不是可用选项之一

但是，当我从DurationField中删除选项并保留默认值时：

duration = models.DurationField(default = MEDIUM)

我可以提交没有任何问题。我在这里做错了什么？

在渲染或转换为模板时，模型选择选项没有给定timedelta字符串

以及模型字段 不工作

我用ChoiceField解决了这个问题

代码：

---

我不知道它是否不被推荐。。。我正在寻找django默认不工作的原因…

也有同样的问题，这个问题在错误修复单中解释

解决此问题的最佳方法是在等待django团队解决此问题时使用此自定义字段：

    """
    This is a temp DurationField with a bugfix
    """
    standard_duration_re = re.compile(
        r'^'
        r'(?:(?P<days>-?\d+) (days, )?)?'
        r'((?:(?P<hours>\d+):)(?=\d+:\d+))?'
        r'(?:(?P<minutes>\d+):)?'
        r'(?P<seconds>\d+)'
        r'(?:\.(?P<microseconds>\d{1,6})\d{0,6})?'
        r'$'
    )

    # Support the sections of ISO 8601 date representation that are accepted by
    # timedelta
    iso8601_duration_re = re.compile(
        r'^P'
        r'(?:(?P<days>\d+(.\d+)?)D)?'
        r'(?:T'
        r'(?:(?P<hours>\d+(.\d+)?)H)?'
        r'(?:(?P<minutes>\d+(.\d+)?)M)?'
        r'(?:(?P<seconds>\d+(.\d+)?)S)?'
        r')?'
        r'$'
    )
    def parse_duration(value):
        """Parses a duration string and returns a datetime.timedelta.

        The preferred format for durations in Django is '%d %H:%M:%S.%f'.

        Also supports ISO 8601 representation.
        """
        match = standard_duration_re.match(value)
        if not match:
            match = iso8601_duration_re.match(value)
        if match:
            kw = match.groupdict()
            if kw.get('microseconds'):
                kw['microseconds'] = kw['microseconds'].ljust(6, '0')
            kw = {k: float(v) for k, v in six.iteritems(kw) if v is not None}
            return datetime.timedelta(**kw)

    class DurationField(CoreDurationField):
        def to_python(self, value):
            if value is None:
                return value
            if isinstance(value, datetime.timedelta):
                return value
            try:
                parsed = parse_duration(value)
            except ValueError:
                pass
            else:
                if parsed is not None:
                    return parsed
            raise exceptions.ValidationError(
                self.error_messages['invalid'],
                code='invalid',
                params={'value': value},
            )

---

看起来那张票的地址是1.8.3

    """
    This is a temp DurationField with a bugfix
    """
    standard_duration_re = re.compile(
        r'^'
        r'(?:(?P<days>-?\d+) (days, )?)?'
        r'((?:(?P<hours>\d+):)(?=\d+:\d+))?'
        r'(?:(?P<minutes>\d+):)?'
        r'(?P<seconds>\d+)'
        r'(?:\.(?P<microseconds>\d{1,6})\d{0,6})?'
        r'$'
    )

    # Support the sections of ISO 8601 date representation that are accepted by
    # timedelta
    iso8601_duration_re = re.compile(
        r'^P'
        r'(?:(?P<days>\d+(.\d+)?)D)?'
        r'(?:T'
        r'(?:(?P<hours>\d+(.\d+)?)H)?'
        r'(?:(?P<minutes>\d+(.\d+)?)M)?'
        r'(?:(?P<seconds>\d+(.\d+)?)S)?'
        r')?'
        r'$'
    )
    def parse_duration(value):
        """Parses a duration string and returns a datetime.timedelta.

        The preferred format for durations in Django is '%d %H:%M:%S.%f'.

        Also supports ISO 8601 representation.
        """
        match = standard_duration_re.match(value)
        if not match:
            match = iso8601_duration_re.match(value)
        if match:
            kw = match.groupdict()
            if kw.get('microseconds'):
                kw['microseconds'] = kw['microseconds'].ljust(6, '0')
            kw = {k: float(v) for k, v in six.iteritems(kw) if v is not None}
            return datetime.timedelta(**kw)

    class DurationField(CoreDurationField):
        def to_python(self, value):
            if value is None:
                return value
            if isinstance(value, datetime.timedelta):
                return value
            try:
                parsed = parse_duration(value)
            except ValueError:
                pass
            else:
                if parsed is not None:
                    return parsed
            raise exceptions.ValidationError(
                self.error_messages['invalid'],
                code='invalid',
                params={'value': value},
            )