We are all familiar with the `with` statement for context managers, so that the resources are correctly finalized/closed in case of an exception either in terms
of the resources being allocated of the processing.

It is very common though to wrap the `with block` in an outer `try` block, since although we know that the resource has been closed, at an 'application' level it is still neccessary
to deal with the exception - an example might be :

try:
    with open('config.cfg', 'r') as cfg:
        # Process the open  file
        config = load_config(cfg)
except FileNotFound:
    logging.info('Config file not found - using default configuration')
except PermissionError:
    logging.warning('Cannot open config .cfg - using default configuration')
    config = default_config()
else:
    logging.info('Using config from config.cfg')

It struck me that this is probably quite a common idiom, and we have the main processing (of the opened resources) indented twice just to accommodate
the outer try block.

I was wondering whether a worthwhile extension might be to allow the `with` statement to have an `except` and  `else` clauses which would have the same
semantics as wrapping the `with` block with a try - for example the above would now look like:

I am not good enough with core development to put together a working prototype, but I can imagine that this simple extension would be worth while, but I would be more than happy to author a PEP for this if it gets some initial positive feedback.

Open questions - that I have - should we allow `except`, `else` and `finally` clauses (or just `except` and `else` - do we need `finally` here).

--