[Python-Dev] Re: PEP-317 (original) (raw)

Raymond Hettinger python@rcn.com
Mon, 9 Jun 2003 21:07:48 -0400

Btw, just to be clear: in pure Python, deferred instantiation is already impossible; implicit instantiation is exactly equivalent to explicit.

Almost exactly:

def f(): raise ValueError, 1

def g(): raise ValueError(1)

from dis import dis dis(f) 2 0 LOAD_GLOBAL 0 (ValueError) 3 LOAD_CONST 1 (1) 6 RAISE_VARARGS 2 9 LOAD_CONST 0 (None) 12 RETURN_VALUE
dis(g) 2 0 LOAD_GLOBAL 0 (ValueError) 3 LOAD_CONST 1 (1) 6 CALL_FUNCTION 1 9 RAISE_VARARGS 1 12 LOAD_CONST 0 (None) 15 RETURN_VALUE

On a separate note, I was experimented with explicit instantiation and noticed an oddity with my editor's autocomplete. Upon typing:

raise TypeError(

the autocompleter looks up the doc string for TypeError and announces:

Inappropriate argument type

when you were likely expecting to be prompted for the exception value. Perhaps the doc string should read like this:

TypeError([exceptionvalue]) --> Exception for inappropriate argument type.

Raymond Hettinger