Just googled it, it's the release date of Python 2.0.

What was so unreasonable about 1.5? That was my first python and it worked perfectly fine.

Old style classes. No way to subclass built-in types. No metaclasses.

Sure, but non of those things made it a bad language, or where really unreasonable things to have left out.

There is a big difference between unreasonable and bad.

Python was always a good language because it was basically the same pseudocode we all scribbled on blackboards anyway -- with the added advantage that computers could execute it.

I just found 1.x to be unreasonable. I also find 3.x unreasonable for unreasonable reasons.

For me it's lack of lexical scoping.