add 3% performance to isDirpath by assuming it's not None/empty and using an exception handler if it is - this should almost never happen so is faster
add 3% performance to isDirpath by assuming it's not None/empty and using an exception handler if it is - this should almost never happen so is faster

xpybuild/xpybuild,xpybuild/xpybuild,xpybuild/xpybuild,xpybuild/xpybuild