Python 2.7 allows indexing an Exception object to access its args list.

>>> e=Exception('foo','bar','baz')
>>> assert e[0] is e.args[0]

This doesn't work in 3.5:

>>> e=Exception('foo','bar','baz')
>>> e.args[0]
'foo'
>>> e[0]
TypeError: 'Exception' object is not subscriptable

This conversion (e[x] -> e.args[x]) seems like it ought to be fairly straightforward to support in 2to3.

There is no way to know through static analysis that the subscript is on an object of type exception. I think this should be closed as won't fix.

> There is no way to know through static analysis that the subscript is on an object of type exception. I think this should be closed as won't fix.

In almost all cases, the variable in question will receive its value via `except ... as e:`.

   try:
       ...
   except (Exception1, Exception2, ...) as e:
       e[0]

Seems to me that it should be possible for 2to3 to handle this large subset of applicable cases via static analysis.

Why was this closed?

As I wrote in a previous comment, this situation can be automatically identified and addressed via static analysis in the vastly-predominant case, where the Exception object is assigned via an `exception ... as exc:` clause.

See the superseding issue; 2to3 is deprecated and headed towards deletion.