保存表单时,我收到此错误:""需要为字段"surveythread"设置一个值,然后才能使用此多对多关系.
Models.py:
class SurveyResult(models.Model):
stay = models.OneToOneField(Stay, related_name='survey')
created = models.DateTimeField(default=datetime.now)
vote = models.BooleanField(default=False)
vote_service = models.BooleanField(default=False)
comment = models.TextField(blank=True, null=True)
def getThreads(self):
return SurveyThread.objects.filter(parent_survey = self)
threads = property(getThreads)
def __unicode__(self):
return self.vote and 'Good' or 'Bad'
class Meta:
get_latest_by = '-created'
class SurveyThread(models.Model):
survey = models.ManyToManyField(SurveyResult, related_name='parent_survey')
email = models.EmailField(max_length=200)
comment = models.TextField(blank=True, null=True)
views.py:
survey_list = SurveyResult.objects.filter(stay__guest__user=request.user) \
.select_related('stay', 'stay__guest')
forms = {}
for survey in survey_list:
forms[survey] = SurveyThreadForm(data=request.POST or None, survey=survey)
if forms[survey].is_valid():
instance = …我试图找出以下查询的Big-Oh性能:
SELECT *
FROM table1 INNER JOIN table2 ON table1.a = table2.b
GROUP BY table1.a
table1.a是表的主键.table2.b上有一个非唯一索引.
我的想法是,因为每一个索引可以在O(log n)的被搜索,然后这个查询为O执行(日志的n*log m),其中n是行的表1中,且m的数量的行的表2中的数量.
任何输入将不胜感激.
我有一个模型注释,创建时可能会也可能不会创建新用户.因此,我的API在创建新评论时需要密码字段.这是我的评论模型:
class Comment(models.Model):
commenter = models.ManyToManyField(Commenter)
email = models.EmailField(max_length=100)
author = models.CharField(max_length=100)
url = models.URLField(max_length=200)
content = models.TextField(blank=True, null=True)
ip = models.IPAddressField(max_length=45)
date = models.DateTimeField(default=datetime.now)
post_title = models.CharField(max_length=200)
post_url = models.URLField(max_length=200)
rating = models.IntegerField(max_length=10, default=0)
这是我的API视图:
class CommentNewView(CreateAPIView):
model = Comment
serializer_class = CommentCreateSerializer
这是我的序列化器:
class CommentCreateSerializer(serializers.ModelSerializer):
commenter_pw = serializers.CharField(max_length=32, required=False)
class Meta:
model = Comment
fields = ('email', 'author', 'url', 'content', 'ip', 'post_title', 'post_url', 'commenter_pw')
这是我得到的错误:
Environment:
Request Method: POST
Request URL: http://127.0.0.1:8000/api/comment/create/
Django Version: 1.5.2
Python Version: 2.7.2 …有人可以告诉我如何从Python中的email.message_from_string()获取发件人地址吗？谢谢!我试过了
message = email.message_from_string(email_text)
from = message['From']
但是,这似乎不起作用.
这是我正在解析的电子邮件:
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