accessor/mutator functions

[mirandacascade at yahoo.com]

When I look at how classes are set up in other languages (e.g. C++), I
often observe the following patterns:
1) for each data member, the class will have an accessor member
function (a Get<whatever> function)
2) for each data member, the class will have a mutator member function
(a Set<whatver> function)
3) data members are never referenced directly; they are always
referenced with the accessor and mutator functions

My questions are:
a) Are the three things above considered pythonic?
b) What are the tradeoffs of using getattr() and setattr() rather than
creating accessor and mutator functions for each data member?