import code

def foo():
    i = 3
    print "Before: i = %r" % i
    interpreter = code.InteractiveInterpreter(locals())
    line = "i = i + 4"
    interpreter.runsource(line, "<console>")
    print "After: i = %r" % i

foo()
j = 4
interpreter = code.InteractiveInterpreter(locals())
line = "j = j + 3"
interpreter.runsource(line, "<console>")
print "After: j = %r" % j