On Fri, Apr 22, 2011 at 6:55 AM, Vlastimil Brom
<vlastimil.b...@gmail.com> wrote:
> Hi all,
> I'd like to ask for comments or advice on a simple code for testing a
> "subdict", i.e. check whether all items of a given dictionary are
> present in a reference dictionary.
> Sofar I have:
>
> def is_subdict(test_dct, base_dct):
> """Test whether all the items of test_dct are present in base_dct."""
> unique_obj = object()
> for key, value in test_dct.items():
> if not base_dct.get(key, unique_obj) == value:
> return False
> return True
>
> I'd like to ask for possibly more idiomatic solutions, or more obvious
> ways to do this. Did I maybe missed some builtin possibility?
> I am unsure whether the check against an unique object() or the
> negated comparison are usual.?
I second MRAB's all() suggestion. The use of object() as a higher-rank
None is entirely normal; don't worry about it.
Also, the following occurs to me as another idiomatic, perhaps more
/conceptually/ elegant possibility, but it's /practically/ speaking
quite inefficient (unless perhaps some dict view tricks can be
exploited):
def is_subdict(sub, larger):
return set(sub.items()).issubset(set(larger.items()))
Cheers,
Chris
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