Pythonic syntax for appending an arbitrary class object list property

Is there an analog of setattr() that allows for appending an arbitrary list property of an instantiated class object? If not, is there a recommended way of doing so?

This is a trivialized version of what I'm doing currently:

foo = SomeClass()
...
attr = "names"
value = "Eric"
values = g开发者_如何学编程etattr(foo, attr)
values.append(value)
setattr(foo, attr, values)

This seems clunky and inefficient.

Edit: this assumes that foo.names (or whatever arbitrary value might be assigned to the attr variable) is in fact a list.

The setattr call is redundant, if foo.names is indeed a list (if it's something else, could you please clarify?). getattr(foo, attr).append(value) is all you need.