Testing a session variable in django

I came across Django Request.Session where, I know how to set and test it for a specific value.

request.session['name'] = "dummy"

and somewhere i check

if request.session['name'] == "dummy" :
   #do something

But, now i have to check whether the session variable was even set in the first place? I mean how can i check whether there exists a value in the Request.Session['name'] Is set ?

Please can anyone tel me, is there a way to check it?

Thank you in advance.