Python - Datastructures

   Keys in dictionary should be of immutable data type (as keys are used for indexing)

* You can use curly braces to define a set like this: {1, 2, 3}. However, if you leave the curly braces empty like this: {} Python will instead create an empty dictionary. So to create an empty set, use set().
** A dictionary itself is mutable, but each of its individual keys must be immutable.

Data Structure	Ordered	Mutable	Constructor	Example
List	Yes	Yes	[ ] or list()	[5.7, 4, 'yes', 5.7]
Tuple	Yes	No	( ) or tuple()	(5.7, 4, 'yes', 5.7)
Set	No	Yes	{}* or set()	{5.7, 4, 'yes'}
Dictionary	No	No**	{ } or dict()	{'Jun': 75, 'Jul': 89}