e of the program.  In Python, variable creation is nothing more
than a naming operation.  For example, when you say '<tt>a = 3</tt>',
'a' becomes a name that refers to some object '3'.  Later on, if you say
'<tt>a = 7.5</tt>, the name 'a' is bound to an entirely different object
containing the value '7.5' (the contents of the original object are not
changed).  The end result of this is that a variable in Python can refer
to a virtually unlimited number of different objects (memory locations)
over the lifeti