Block Scope

########################
# foobar.py

x = 10

class _Foobar:
    @property
    def y(self):
        global x
        return x + 32

import sys
_ref, sys.modules[__name__] = sys.modules[__name__], _Foobar()

########################
# test_foobar.py

import foobar

# Use existing module property.
print(foobar.y)  # -> 42

# Dynamically add a property to the module.
foobar.a = 3
foobar.__class__.b = property(lambda self: self.a + 1)
print(foobar.b)  # -> 4