How to modify the form filed data? - django

Question

I have a model:
class PastStudy(Model):
grade_average = FloatField(null=True)
I have a modelform as below:
class PastStudyForm(ModelForm):
class Meta:
model = PastStudy
fields = ('grade_average', )
What I have in view:
...
if request.POST:
past_study_form = PastStudyForm(request.POST)
if past_study_form.is_valid():
return HttpResponse(past_study_form.cleaned_data['grade_average'])
else:
profile_filter_past_study_form = ProfileFilterPastStudyForm()
...
What I need is that I want to write a clean method for PastStudyForm so that in case I entered 90 as grade average, HttpResponse converts it two 0-20 grading scheme and returns 18.
I tried this and I was still getting 90 not 18
class PastStudyForm(ModelForm):
class Meta:
model = PastStudy
fields = ('grade_average', )
def clean(self):
cleaned_data = super().clean()
grade_average = self.cleaned_data['grade_average']
self.cleaned_data['grade_average'] = grade_average/5
return cleaned_data
and This:
class PastStudyForm(ModelForm):
class Meta:
model = PastStudy
fields = ('grade_average', )
def clean_grade_average(self):
grade_average = self.cleaned_data['grade_average']
data = grade_average/5
return data
However, I still get 90. I also have tried a few other methods but I still was getting 90 in HttpResponse
Maybe using clean method be wrong and I should do something else!
The real code is huge and I have summarized it in here and other aspects of the problem are not explained in here. That is why I prefer and expect to get a response in which I am advised how to it in the form definition, not other methods such as converting it in the view.

Answer 1

in your clean method, you assign the result of your calculation method into self.cleaned_data,
while you are returning cleaned_data not self.cleaned_data.
it is different variable.
try this instead:
self.cleaned_data = super().clean()
grade_average = self.cleaned_data['grade_average']
self.cleaned_data['grade_average'] = grade_average/5
return self.cleaned_data