>>> dict([ ('a',1), ('b',2)  ]) 
--> {'a': 1, 'b': 2}

>>> dict([ ('a',1), ('b',2) , ('c',3) ])
--> {'a': 1, 'b': 2, 'c': 3}

>>> d=dict([ ('a',1), ('b',2) , ('c',3) ])

>>> d['a']
--> 1

>>> d['c']
--> 3
