What is significance of Tuples in Python? Can someone please explain with example

Question

I gone through the RFC4006 but didnt get the context of below paragraph

   Certain applications require multiple credit-control sub-sessions.
   These applications would send messages with a constant Session-Id
   AVP, but with a different CC-Sub-Session-Id AVP.  If several credit
   sub-sessions will be used, all sub-sessions MUST be closed separately
   before the main session is closed so that units per sub-session may
   be reported.  The absence of this AVP implies that no sub-sessions
   are in use.

But here my question is
1. What could be the types of Multiple credit-ontrol Sub-session?
2. How can we include different cc-sub-session-ID for each sub-session, please give me an example with message structure using CCR message.

Answer 1

A tuple is a sequence of immutable Python objects. Tuples are sequences, just like lists. The only difference is that tuples can't be changed i.e., tuples are immutable.

Example

tup = ('query', 'home');

The empty tuple is written as two parentheses containing nothing:

tup = ();

To write a tuple containing a single value you have to include a comma even if it has only one value.

tup = (10,);

Like string indices, tuple indices start at 0, and tuples can be sliced, concatenated and so on.

Accessing Values in Tuples:
To access values in tuple, use the square brackets for slicing along with the index

#!/usr/bin/python

tup = ('query', 'home'); 
print "tup[0]: ", tup[0]

Output
tup1[0]:  query