I agree that Python's default string interpolation sucks, but it's simple enough to fix. Just import the sys and Itpl  libraries and write sys.stdout=Itpl.filter() to get real string interpolation. Definitely not as clean as native string interpolation, but if that's a deal-breaker for anybody, it's easy enough to fix.
String interpolation by default is a _bad_ thing. It introduces unexpected behavior which are frequently security holes. Explicit interpolate(string, map) of some sort is better.# Oliver X