[Python-Dev] Can Python implementations reject semantically invalid expressions?

[Craig Citro]

> This question has an easy answer - can you possibly tell the difference?
>

Ok, I'm obviously being silly here, but sure you can:

>>> dis.dis("raise TypeError()")
          0 <114>           26977
          3 <115>            8293
          6 IMPORT_STAR
          7 SETUP_EXCEPT    25968 (to 25978)
         10 <69>
         11 <114>           28530
         14 <114>           10536
>>> dis.dis("1 + '1'")
          0 <49>
          1 SLICE+2
          2 STORE_SLICE+3
          3 SLICE+2
          4 <39>
          5 <49>
          6 <39>

That said, I agree with the point you're making -- they have the same
semantics, so you should be fine substituting one for the other.

Honestly, though, I'd come down on the side of letting the compiler
raise an error -- while I understand that it means you have
*different* behavior, I think it's *preferable* behavior.

-cc