Django 1.6：MultiValueDictKeyError错误

Question

我正在尝试实现一个平均等待时间的功能，让用户可以输入医生的等待时间。但是我一直遇到这个错误，完全不知道该怎么解决。我试着查找资料，但还是搞不清楚。

Traceback:
File "/Library/Python/2.7/site-packages/django/core/handlers/base.py" in get_response
  114.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Library/Python/2.7/site-packages/django/contrib/auth/decorators.py" in _wrapped_view
  22.                 return view_func(request, *args, **kwargs)
File "views.py" in addWaitingTime
  111.     time = escape(post['time'])
File "/Library/Python/2.7/site-packages/django/utils/datastructures.py" in __getitem__
  301.             raise MultiValueDictKeyError(repr(key))

Exception Type: MultiValueDictKeyError at /waiting_time/
Exception Value: "'time'"

views.py

@login_required
def addWaitingTime(request):
    post = request.POST
    time = escape(post['time'])
    doctor_seeker = post['userId']
    doctor = post['doctorId']

    if len(time) > 1:
        newTime = WaitingTime(time=time, doctor_seeker_id = userId, doctor_id = doctorId)
        newTime.save()

    url = "/docprofile/"+str(doctor_id)+"/"
    return HttpResponseRedirect(url)

models.py

class WaitingTime(models.Model):
    time_choices = ( (10, 'Less than 10 Minutes'), (20, 'Less than 20 Minutes'), (30, 'Less than 30 Minutes'))
    time = models.IntegerField(choices = time_choices)
    doctor_id = models.IntegerField()
    doctor_seeker_id = models.IntegerField()

    def __unicode__(self):
        return u"%s %s" % (self.time, self.doctor_id)

class Doctor(models.Model):
    name = models.CharField(max_length=30)
    specialization = models.ForeignKey(Specialization)
    clinic = models.ForeignKey(Clinic)
class DoctorSeeker(models.Model):
    name = models.CharField(max_length=30)
    email = models.EmailField()
    user = models.OneToOneField(User, unique=True)

Answer 1

正如cchristelis所说，这个错误是因为你的POST数据里没有time这个值。

其实对于这种情况，你应该使用Django的表单框架。这是验证用户输入和处理这些输入的正确工具。

Answer 2

问题是，帖子对象中没有名为'time'的变量。

我建议你：

1) 查看一下帖子对象的具体内容，可以通过打印出来或者写入文件的方式来查看。（我觉得你可能是用的get而不是post。）

2) 在处理用户输入的数据时，要始终做好准备，可能会和你预期的不一样。（比如，有恶意用户或者爬虫可能在访问你的网站。）最好使用：

time = post.get('time')
if time:
    time = escape()
else:
    # No time value was submitted ....