[PythonicAlpha]

This special syntax should be discouraged for any strings that shall be translated in the future. Different languages have different syntax, so the order can change, with this kind of syntax, you will be in big trouble very soon!

[nostrademons]

For anything translated, you'd use the (admittedly gross, fixed in Python3) "Welcome %(who)s to %(place)s" % { 'who': who, 'place': place }. The Python3 version is "Welcome {who} to {place}".format(place=place, who=who), or if you want to be un-idiomatic and unsafe, "Welcome {who} to {place}".format(locals())