Pythonic way to check empty dictionary and empty values

Question

I am using these kind of dictionaries, they can be or totally empty like collection_a or contain a single one level nested dictionary which might be empty. It wont have more levels.

collection_a = {}
collection_b = {"test": {}}

print is_empty(collection_a)
print is_empty(collection_b)

def is_empty(collection):
    return not all(collection.values())

or

def is_empty(collection):
    return not bool(collection.values())

Isnt there an unique way to check if a or b have values?

You can check all(collection_b.values()) but that wont work for collection_a where it will return True

You can also check bool(collection_a.values()) but that wont work for collection_b where it will return True...

Isnt there an unique way to include both cases?

Answer 1

Test with any, since empty dicts are falsy:

>>> collection_a = {}
>>> collection_b = {"test": {}}
>>> any(collection_a.values())
False
>>> any(collection_b.values())
False

This assumes that the dictionary value is always a dictionary.

Answer 2

If you want to check whether the dictionary has values, and whether all the values (if any) are "truthy", just combine your two tests:

bool(collection) and all(collection.values())

(The bool in the first part is optional, but without it you will get an unintuitive {} if the dictionary is empty.)

Of course, if you only want to check whether any of the values in the collection are "truthy" (this is not entirely clear from your question), all you have to do is any(collection), as already stated in other answers; this will at the same time also check whether the collection is non-empty.