mihai.ibanescu.net

I ran into a piece of code that looked like this:

import threading

class A(threading.Thread):
    def run(self):
        self.foo()

    def foo(self):
        assert(threading.currentThread() != self, "Blah?")
        print threading.currentThread() == self

a = A()
a.start()
a.foo()
a.join()

In the original code, there was no a.foo() invocation, because that would have triggered the assertion. Or so it was thought. I added it for my own edification.

The intention was for the foo() method to be callable only from within the running thread. In my quick test above, a.foo() should have failed.

There were two problems with that piece of code. First, it was not failing. Second, in python 2.6 you get a warning whenever you use assert with paranthesis. This is very deliberate, since assert is not a function. Using paranthesis will simply pass a tuple to the assert construct, and the tuple will always evaluate to True.

Very dutifully, I removed the paranthesis, and moved on to do some other things (and I even forgot I did it). A few days later, a coworker reported problems with the code.

As it turned out, the assert was hiding a very old bug – the condition should have checked for equality, not inequality. But since the condition _and_ the error message were paranthesized, the code passed no matter what you did. Removing the warning uncovered the problem, probably 3 years later.

If you needed an excuse-of-the-day look no further than the DMTF specs for CIM.

The CIM_Error class has a ProbableCause property which can have a long list of values:

http://msdn.microsoft.com/en-us/library/cc150671(VS.85).aspx

“Toxic Leak Detected”, “Ice Buildup”, “High Winds”.

In a way, I feel refreshed to see the potential causes for the world’s problems are no more than 129.

Flying back from Romania, we had a one-night layover in Vienna, Austria, and we spent the evening sightseeing.

Here is the dinner-on-the-run we got from a supermarket (we wanted to use the daylight for pictures, so we chose to eat at the hotel instead of a restaurant in the city).

The Limburger was not “ripe” yet (i.e. it was still firm; as with the Camembert, if you let it outside for a few hours, it will become soft and spreadable – and extremely smelly). Off the supermarket shelves, one only gets a hint of how rotten it will become.

In the train that was taking us back to the hotel, every time I was opening by backpack, I was afraid the HAZMAT unit will show up and throw us out.

The cheese strudel was pretty good too, but it had no good story behind it.