[scoppini]

I think it could be ambiguous in certain situations. Let's say I wanted to conditionally set a variable to one of two negative constants. In the current syntax, that would look like:

  x = -1 if y else -2

However, with your syntax, it would look like:

  x = if y -1 else -2

Which could be possibly confused with trying to subtract 1 from y.

[oxryly1]

Ah, and Python uses whitespace and colons to disambiguate, which would ruin the efficiency of this form.