On 8/25/2015 10:32 AM, random...@fastmail.us wrote:
On Mon, Aug 24, 2015, at 22:12, Andrew Wang wrote:
[question snipped]

And, now, your moment of zen:

Huh??  I fail to see the point of this buggy code.

def isa(ob, cl):
   try:
       raise ob
   except cl:
       return 1
   else: return 0

The extra marginal '>' quote makes it look like this buggy code was posted by Andrew, but it comes from random832. In 3.x, both ob and cl must be exceptions and isa(1, int) cannot work. In 2.7, ob must be an exception or old-style class (not documented that I see).

>>> raise 1

Traceback (most recent call last):
  File "<pyshell#32>", line 1, in <module>
    raise 1
TypeError: exceptions must be old-style classes or derived from BaseException, not int

Hence, isa(1, int) raises TypeError instead of returning 1. If 'else' is changed to 'except', it returns 0 instead of 1.

--
Terry Jan Reedy

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