Printing dict value for possibly undefined key

[DL Neil]

On 11/25/2023 3:31 AM, Loris Bennett via Python-list wrote:
> Hi,
> 
> I want to print some records from a database table where one of the
> fields contains a JSON string which is read into a dict.  I am doing
> something like
> 
>    print(f"{id} {d['foo']} {d['bar']}")
> 
> However, the dict does not always have the same keys, so d['foo'] or
> d['bar'] may be undefined.  I can obviously do something like
> 
>    if not 'foo' in d:
>      d['foo']="NULL"
>    if not 'bar' in d:
>      d['bar']="NULL"
>    print(f"{id} {d['foo']} {d['bar']}")
> 
> Is there any more compact way of achieving the same thing?


What does "the dict does not always have the same keys" mean?

a) there are two (or...) keys, but some records don't include both;

b) there may be keys other than 'foo' and 'bar' which not-known in-advance;

c) something else.


As mentioned, dict.get() solves one of these.

Otherwise, there are dict methods which collect/reveal all the keys, all 
the values, or both - dict.keys(), .values(), .items(), resp.

--
Regards =dn