What is the difference between context.push() and context.update() in Django Context

Question

From the documentation, I understand that the context object is a stack. Then what are push() and update() doing with respect to this code segment? It is stated in the doc that push() and update() are similar but update() takes a dictionary as argument. Then why are we using them simultaneously here?

import django.template
import django.template.loader

def render(name, *values):
    ctx = django.template.Context()
    for d in values:
        ctx.push()
        ctx.update(d)

    t = django.template.loader.get_template(name)
    return str(t.render(ctx))

Also, what is the need of having context object as a stack?

Edit : I went through the doc again and found the flatten() function which flattens all the levels in the stack to make them comparable.

Answer 1

The only difference seems to be (also according to the tests) the way you pass arguments into the call. Update takes a dictionary while push takes keyword arguments.

And about the usefulness, the documentation says:

Using a Context as a stack comes in handy in some custom template tags.