Updating python dictionary

[John Machin]

On Sep 8, 8:42 am, "James Mills" <prolo... at shortcircuit.net.au> wrote:
> On Mon, Sep 8, 2008 at 8:37 AM, John Machin <sjmac... at lexicon.net> wrote:

> > There seems to be an implicit assumption in the answers so far that
> > your mapping is a 1:1 mapping of all possible input keys.
>
> > If it doesn't include all possible input keys, answers will crash with
> > a KeyError. If there are any many:1 elements in the mapping (for
> > example, {'a': 'A', 'b': 'A'}), lossage happens. You may wish to code
> > in some checks for this.
>
> You are quite right! But then he/she didn't
> ask for this right ? :)
>

What do you mean by "this right"? Perhaps the Divine Right of OPs,
managers, examiners, business analysts, etc never to give a complete
spec up front and never to contemplate the consequences of Murphy's
Law?