It does have a name, namely the argument name.  It doesn't need two names though, like is done here.  People generally don't 'declare' variables in dynamic languages.  That is the whole reason for them.  

Still, I agree that it is always better to be explicit.  So if you want, this could be `determ_analysis(niter=100)` since Python allows the programmer to assign to arguments in the function call.  I am +1 to that here.  I was just being lazy :)