Yury Selivanov wrote:
Re "raise ValueError from ..."

So what does it mean now?  Just resetting __cause__ to make __context__ printed?

Whatever __cause__ was before (None, or an actual exception), it is now Ellipsis -- so __context__ will be printed and the exception chain will be followed.

Can you show the down-to-earth snippet of code where such syntax would be 
useful?

Not sure I'll ever use it this way, but:

try:
  try:
    raise IndexError()
  except:
    raise CustomError() from None
except CustomError as e:
  # nevermind, let's see the whole thing after all
  raise e from Ellipsis

~Ethan~
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
http://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: 
http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com

Reply via email to