Development quote of the week

Still, even with this, it was never going to be a matter of just following some standard porting advice and calling it good. Launchpad has almost a million lines of Python code in its main git tree, and around 250 dependencies of which a number are quite Launchpad-specific. In a project that size, not only is following standard porting advice an extremely time-consuming task in its own right, but just about every strange corner case is going to show up somewhere. (Did you know that StringIO.StringIO(None) and io.StringIO(None) do different things even after you account for the native string vs. Unicode text difference? How about the behaviour of .union() on a subclass of frozenset?) Launchpad’s test suite is fortunately extremely thorough, but even just starting up the test suite involves importing most of the data model code, so before you can start taking advantage of it you have to make a large fraction of the codebase be at least syntactically-correct Python 3 code and use only modules that exist in Python 3 while still working in Python 2; in a project this size that turns out to be a large effort on its own, and can be quite risky in places.