-1 as a url parameter in Django
Django only accepts positive integers as url parameters.
Invalid urls.py:
1urlpatterns = [
2path("<str:chart_name>/step/<int:step>", views.chart_step, name="chart_step"),
3]
It doesn’t really matter how we structure our view, since we receive an error nonetheless:
views.py:
1def chart_step(request, chart_name, step):
2
3output = (
4
5Chart.objects.filter(chart_name=chart_name)
6
7.get()
8
9.persona_set.filter(step=step)
10
11)
12
13return HttpResponse(output)
But say, we have a step parameter which receives values from -9999 to 0 to +9999?
We have to receive the parameter in urls.py in a different format, a different type to be exact. I chose to receive it as str:
valid urls.py:
1urlpatterns = [
2path("<str:chart_name>/step/<str:step>", views.chart_step, name="chart_step"),
3]
Since I defined the column in models.py to be an IntegerField, I can’t pass this string-parameter directly to the view. I will have to typecast it into an int, by adapting my view function.
valid views.py:
1def chart_step(request, chart_name, step):
2
3output = (
4
5Chart.objects.filter(chart_name=chart_name)
6
7.get()
8
9.persona_set.filter(step=int(step))
10
11)
12
13return HttpResponse(output)
Now Django accepts the negative value and returns the corresponding database entries.