django fixtures DateTimeField runtimeWarning

Question

我已经为我的django项目设置了一些基本的fixture。插入数据库中的一条记录如下所示：

  {
    "model": "articles.article",
    "pk": 1,
    "fields": {
      "title": "Blackened Recordings Launches",
      "headline": "we're so psyched about our new adventure",
      "content": "<p>We like to make it a point here not to bore you with the not-so-exciting business aspects of making and sharing music, but we're so psyched about our new adventure that we just had to tell you about it as we officially launch our very own record label, Blackened Recordings.</p><p>Some of you, who have followed along throughout the years, are aware that in 1994 we renegotiated our contract with the Warner Music Group, which resulted in a joint venture with our record company for releasing all of our recordings including long form videos. Per that agreement, as of today we have taken ownership of all of our master recordings and Blackened Recordings will be the home of all of our current albums and videos along with all future releases including the December 10 release of the \"Quebec Magnetic\" DVD and Blu-ray.</p><p>You may have heard us say it once or twice or a thousand times before, but it's always been about us taking control of all things 'Tallica to give you 110% on every single level every single time. Forming Blackened Recordings is the ultimate in independence, putting us in the driver's seat of our own creative destiny. We're looking forward to making more music and getting it all out to you in our own unique way.</p>",
      "image": "examples/slide-03.jpg",
      "active": 1,
      "created_at": "2013-03-16 17:41:28"
    }
  },

这是它所对应的模型：

class Article(models.Model):
    """News article, displayed on homepage to attract users"""
    class Meta:
        db_table = 'article'
    title = models.CharField(max_length=64)
    headline = models.CharField(max_length=255)
    content = models.TextField()
    image = models.ImageField(upload_to = 'articles/', null=True, blank=True)
    active = models.BooleanField()
    created_at = models.DateTimeField()
    def __unicode__(self):
        return self.title

在插入装置记录时，我收到以下警告：

/usr/local/lib/python2.7/dist-packages/django/db/models/fields/__init__.py:827: RuntimeWarning: DateTimeField received a naive datetime (2013-03-16 17:41:28) while time zone support is active.
  RuntimeWarning)

我不知道这里出了什么问题。我尝试使用this blog post，但我确实安装了pytz，并且在我的settings.py中有USE_TZ=True选项。

Answer 1

实际上，解决方案深深地隐藏在python docs中，引用如下：

序列化aware datetime时，会包括UTC偏移量，如下所示：

"2011-09-01T13:20:30+03:00"

这样的装置是完全接受的，在我的例子中是：

"2013-03-16T17:41:28+00:00"
"2013-03-17T23:36:12+00:00"
"2013-03-18T13:19:37+00:00"

输出结果是：

$ ./manage.py loaddata articles/fixtures/initial_data.json 
Installed 3 object(s) from 1 fixture(s)

请注意，'2013-03-16 17:41:28 UTC+0000'不是正确的时区感知datetime格式，它将显示以下错误：

DeserializationError: Problem installing fixture 'articles/fixtures/initial_data.json': [u"'2013-03-16 17:41:28 UTC+0000' value has an invalid format. It must be in YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."]

Answer 2

另外，如果您正在使用yaml进行序列化，那么在PyYaml中反序列化datetime似乎存在一个错误

https://code.djangoproject.com/ticket/18867

可以尝试使用json作为序列化程序，也可以在.yaml文件中的日期时间两边添加引号。

Answer 3

您可能应该仔细查看created_at字段(您是否使用know about auto_now_add=True?)。

我在猜测你使用的是什么，所以你可以尝试像这样的东西

import datetime
from django.utils.timezone import utc

Article.created_at = datetime.datetime.utcnow().replace(tzinfo=utc)

或者，您可以通过设置禁用时区支持

USE_TZ = False

在你的settings.py中

或者你可以让你不知道的datetime知道

import datetime
import pytz
utc=pytz.UTC

#  where ever you get your datetime from
unaware = datetime.datetime(2013,3,16,17,41,28,0)

now_aware = utc.localize(unaware)