Question

Django code samples involving post data often shows code similar to this:

if request.method == "POST":
   post = request.POST.copy()
   #do stuff with post data

Is there a reason for copying the post data instead of working with it directly?

Answer 1

I think it is because request.POST itself is defined immutable. If you want a version you can actually change (mutability), you need a copy of the data to work with.

See this link (request.POST is a QueryDict instance).

---

class QueryDict

QueryDict instances are immutable, unless you create a copy() of them. That means you can’t change attributes of request.POST and request.GET directly.