__init__.py

# Part of a package named foo.

__all__ = []

def export(defn):
    """Decorator to explicitly mark functions that are exposed in a lib."""
    globals()[defn.__name__] = defn
    __all__.append(defn.__name__)
    return defn

from . import foo

foo.py

# Part of a package named foo.

# How can I expose this variable TIMING_ENABLED when someone imports this package? 
TIMING_ENABLED = True

class Foo(object):
    def set_foo(self, val):
        self.val = val

# How about this one? 
foo = Foo()