Python群集型態整理

常用的Python群集型態有list, tuple, set, dict，把它們的特性整理一下

	List	Tuple	Set	Dict
element type	object	object	object	key-value (object-object)
ordered	Y	Y	N	N
mutable	Y	N	Y	Y
duplicable	Y	Y	N	N (unique key)
example	[1, 'b', 3, 3]	(1, 'b', 3, 3)	{1, 'b', 3}	{'a': 1, 'b': 'hello', 'c': 'hello'}