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.

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

Because what they actually want is something like:

    checkSomeValue() && doOtherThing()

Because that scans as:

Variable x should be assigned if condition a true, otherwise b.

But "condition" is just a placeholder. A concrete example would be:

   msg = if (status == 0) "done" else "error"

Take away the parens (which python is pretty explicit such structure should not be required to be legible).

msg = if status == 0 "done" else "error"

From a compiler perspective that's a bear to parse.

too much like perl?