On Oct 2, 2017, at 17:36, Guido van Rossum <gu...@python.org> wrote: > I've seen your updates and it is now acceptable, except for *one* nit: in > builtins.breakpoint() the pseudo code raises RuntimeError if > sys.breakpointhook is missing or None. OTOH sys.breakpointhook() just issues > a RuntimeWarning when something's wrong with the hook. Maybe > builtins.breakpoint() should also just warn if it can't find the hook? > Setting `sys.breakpointhook = None` might be the simplest way to > programmatically disable breakpoints. Why not allow it?
Oh, actually the pseudocode doesn’t match the C implementation exactly in this
regard. Currently the C implementation is more like:
def breakpoint(*args, **kws):
import sys
missing = object()
hook = getattr(sys, 'breakpointhook', missing)
if hook is missing:
raise RuntimeError('lost sys.breakpointhook')
return hook(*args, **kws)
The intent being, much like the other sys-hooks, that if
PySys_GetObject("breakpointhook”) returns NULL, Something Bad Happened, so we
have to set an error string and bail. (PySys_GetObject() does not set an
exception.)
E.g.
>>> def foo():
... print('yes')
... breakpoint()
... print('no')
...
>>> del sys.breakpointhook
>>> foo()
yes
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in foo
RuntimeError: lost sys.breakpointhook
Setting `sys.breakpoint = None` could be an interesting use case, but that’s
not currently special in any way:
>>> sys.breakpointhook = None
>>> foo()
yes
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in foo
TypeError: 'NoneType' object is not callable
I’m open to special-casing this if you think it’s useful.
(I’ll update the pseudocode in the PEP.)
Cheers,
-Barry
signature.asc
Description: Message signed with OpenPGP
_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
