Ruby 1.8 to 1.9 was a similar mess for a shorter period of time, and not because it was handled better, but because there was less diverse entrenched code and subcommunities to deal with: when Rails and popular Rails libraries worked, most of the community could move; Python had a whole lot more that had to be addressed, the curse of it's broader success.
(Also, being already expression-oriented, Ruby didn't have to deal with running into problems where a core feature was a statement that couldn't be used in contexts limited to expressions; fixing that is inherently painful.)
(Also, being already expression-oriented, Ruby didn't have to deal with running into problems where a core feature was a statement that couldn't be used in contexts limited to expressions; fixing that is inherently painful.)