accessing module global vars by name

[Martin Drautzburg]

Withing a module I can assign a value to a global var by assigning to
it in the outermost scope. Fine.

But how can I do this if the attribute name itself is kept in a
variable. Once the module is loaded I can access the module's
namespace no problem, but inside the module the dictionary is not yet
present right ?

IOW how can I write something like

# xxx.py

for varName in ("foo", "bar"):
        magic.varName = 1

so I can later refer to them as 

# yyy.py
        import xxx
        x = xxx.foo
        y = xxx.bar